From b6ebee45cbaf053770300268de4cb4d71699ceb8 Mon Sep 17 00:00:00 2001
From: MGatner <mgatner@icloud.com>
Date: Tue, 1 Jun 2021 00:47:08 +0000
Subject: [PATCH 1/8] Rebrand Mailer

---
 app/Config/Mailer.php                         |  168 ++
 system/Config/Services.php                    |   39 +
 system/Language/en/Mailer.php                 |   36 +
 system/Mailer/Exceptions/MailerException.php  |   97 +
 system/Mailer/Handlers/BaseHandler.php        | 1676 +++++++++++++++++
 system/Mailer/Handlers/MailHandler.php        | 1634 ++++++++++++++++
 system/Mailer/Handlers/SMTPHandler.php        | 1638 ++++++++++++++++
 system/Mailer/Handlers/SendmailHandler.php    | 1638 ++++++++++++++++
 system/Mailer/MailerInterface.php             |   59 +
 system/Mailer/Message.php                     | 1220 ++++++++++++
 .../_support/Mailer/ci-logo-not-readable.png  |  Bin 0 -> 4537 bytes
 tests/_support/Mailer/ci-logo.png             |  Bin 0 -> 4537 bytes
 tests/system/Config/ServicesTest.php          |   13 +
 tests/system/Mailer/MailerTest.php            |  579 ++++++
 14 files changed, 8797 insertions(+)
 create mode 100644 app/Config/Mailer.php
 create mode 100644 system/Language/en/Mailer.php
 create mode 100644 system/Mailer/Exceptions/MailerException.php
 create mode 100644 system/Mailer/Handlers/BaseHandler.php
 create mode 100644 system/Mailer/Handlers/MailHandler.php
 create mode 100644 system/Mailer/Handlers/SMTPHandler.php
 create mode 100644 system/Mailer/Handlers/SendmailHandler.php
 create mode 100644 system/Mailer/MailerInterface.php
 create mode 100644 system/Mailer/Message.php
 create mode 100644 tests/_support/Mailer/ci-logo-not-readable.png
 create mode 100644 tests/_support/Mailer/ci-logo.png
 create mode 100644 tests/system/Mailer/MailerTest.php

diff --git a/app/Config/Mailer.php b/app/Config/Mailer.php
new file mode 100644
index 000000000000..b6969cde9713
--- /dev/null
+++ b/app/Config/Mailer.php
@@ -0,0 +1,168 @@
+<?php
+
+namespace Config;
+
+class Mailer
+{
+	/**
+	 * @var string
+	 */
+	public $fromEmail;
+
+	/**
+	 * @var string
+	 */
+	public $fromName;
+
+	/**
+	 * Enable word-wrap
+	 *
+	 * @var boolean
+	 */
+	public $wordWrap = true;
+
+	/**
+	 * Character count to wrap at
+	 *
+	 * @var integer
+	 */
+	public $wrapChars = 76;
+
+	/**
+	 * Type of mail, either 'text' or 'html'
+	 *
+	 * @var string
+	 */
+	public $mailType = 'text';
+
+	/**
+	 * Character set (utf-8, iso-8859-1, etc.)
+	 *
+	 * @var string
+	 */
+	public $charset = 'UTF-8';
+
+	/**
+	 * Whether to validate the email address
+	 *
+	 * @var boolean
+	 */
+	public $validate = false;
+
+	/**
+	 * Email Priority. 1 = highest. 5 = lowest. 3 = normal
+	 *
+	 * @var integer
+	 */
+	public $priority = 3;
+
+	/**
+	 * Newline character. (Use “\r\n” to comply with RFC 822)
+	 *
+	 * @var string
+	 */
+	public $CRLF = "\r\n";
+
+	/**
+	 * Newline character. (Use “\r\n” to comply with RFC 822)
+	 *
+	 * @var string
+	 */
+	public $newline = "\r\n";
+
+	/**
+	 * Enable BCC Batch Mode.
+	 *
+	 * @var boolean
+	 */
+	public $BCCBatchMode = false;
+
+	/**
+	 * Number of emails in each BCC batch
+	 *
+	 * @var integer
+	 */
+	public $BCCBatchSize = 200;
+
+	/**
+	 * Enable notify message from server
+	 *
+	 * @var boolean
+	 */
+	public $DSN = false;
+
+	//-------------------------------------------------------
+	// Mailer properties
+	//-------------------------------------------------------
+
+	/**
+	 * The "user agent"
+	 *
+	 * @var string
+	 */
+	public $userAgent = 'CodeIgniter';
+
+	/**
+	 * The mail sending protocol: mail, sendmail, smtp
+	 *
+	 * @var string
+	 */
+	public $protocol = 'mail';
+
+	/**
+	 * The server path to Sendmail.
+	 *
+	 * @var string
+	 */
+	public $mailPath = '/usr/sbin/sendmail';
+
+	/**
+	 * SMTP Server Address
+	 *
+	 * @var string
+	 */
+	public $SMTPHost;
+
+	/**
+	 * SMTP Username
+	 *
+	 * @var string
+	 */
+	public $SMTPUser;
+
+	/**
+	 * SMTP Password
+	 *
+	 * @var string
+	 */
+	public $SMTPPass;
+
+	/**
+	 * SMTP Port
+	 *
+	 * @var integer
+	 */
+	public $SMTPPort = 25;
+
+	/**
+	 * SMTP Timeout (in seconds)
+	 *
+	 * @var integer
+	 */
+	public $SMTPTimeout = 5;
+
+	/**
+	 * Enable persistent SMTP connections
+	 *
+	 * @var boolean
+	 */
+	public $SMTPKeepAlive = false;
+
+	/**
+	 * SMTP Encryption. Either tls or ssl
+	 *
+	 * @var string
+	 */
+	public $SMTPCrypto = 'tls';
+
+}
diff --git a/system/Config/Services.php b/system/Config/Services.php
index 9dca50115f51..87fc1210ff5b 100644
--- a/system/Config/Services.php
+++ b/system/Config/Services.php
@@ -69,6 +69,7 @@
 use Config\Format as FormatConfig;
 use Config\Honeypot as HoneypotConfig;
 use Config\Images;
+use Config\Mailer as MailerConfig;
 use Config\Migrations;
 use Config\Pager as PagerConfig;
 use Config\Services as AppServices;
@@ -95,6 +96,7 @@
  */
 class Services extends BaseService
 {
+<<<<<<< HEAD
     /**
      * The cache class provides a simple way to store and retrieve
      * complex data for later.
@@ -382,6 +384,43 @@ public static function logger(bool $getShared = true)
         return new Logger(config('Logger'));
     }
 
+	//--------------------------------------------------------------------
+
+    /**
+     * The Mailer class lets you send composed messages via mail, sendmail, SMTP.
+     *
+     * @param MailerConfig|null $config
+     * @param boolean $getShared
+     *
+     * @return \CodeIgniter\Mailer\MailerInterface
+     */
+    public static function mailer($config = null, bool $getShared = true)
+    {
+        if ($getShared)
+        {
+            return static::getSharedInstance('mailer', $config);
+        }
+
+        if (empty($config))
+        {
+            $config = new \Config\MailerConfig();
+        }
+
+        $protocolMap = [
+            'mail'     => 'MailHandler',
+            'sendmail' => 'SendmailHandler',
+            'smtp'     => 'SMTPHandler',
+        ];
+
+        $handler   = '\\CodeIgniter\\Mailer\\Handlers\\' . ($protocolMap[$config->protocol ?? 'mail'] );
+        $mailer = new $handler($config);
+        $mailer->setLogger(static::logger(true));
+
+        return $mailer;
+    }
+
+    //--------------------------------------------------------------------
+
     /**
      * Return the appropriate Migration runner.
      *
diff --git a/system/Language/en/Mailer.php b/system/Language/en/Mailer.php
new file mode 100644
index 000000000000..b5c49c818c7d
--- /dev/null
+++ b/system/Language/en/Mailer.php
@@ -0,0 +1,36 @@
+<?php
+/**
+ * Messenger language strings.
+ *
+ * @package    CodeIgniter
+ * @author     CodeIgniter Dev Team
+ * @copyright  2019-2020 CodeIgniter Foundation
+ * @license    https://opensource.org/licenses/MIT	MIT License
+ * @link       https://codeigniter.com
+ * @since      Version 3.0.0
+ * @filesource
+ *
+ * @codeCoverageIgnore
+ */
+
+return [
+   'mustBeArray'          => 'The email validation method must be passed an array.',
+   'invalidAddress'       => 'Invalid email address: {0}',
+   'attachmentMissing'    => 'Unable to locate the following email attachment: {0}',
+   'attachmentUnreadable' => 'Unable to open this attachment: {0}',
+   'noFrom'               => 'Cannot send mail with no "From" header.',
+   'noRecipients'         => 'You must include recipients: To, Cc, or Bcc',
+   'sendFailurePHPMail'   => 'Unable to send email using PHP mail(). Your server might not be configured to send mail using this method.',
+   'sendFailureSendmail'  => 'Unable to send email using PHP Sendmail. Your server might not be configured to send mail using this method.',
+   'sendFailureSmtp'      => 'Unable to send email using PHP SMTP. Your server might not be configured to send mail using this method.',
+   'sent'                 => 'Your message has been successfully sent using the following protocol: {0}',
+   'noSocket'             => 'Unable to open a socket to Sendmail. Please check settings.',
+   'noHostname'           => 'You did not specify a SMTP hostname.',
+   'SMTPError'            => 'The following SMTP error was encountered: {0}',
+   'noSMTPAuth'           => 'Error: You must assign a SMTP username and password.',
+   'failedSMTPLogin'      => 'Failed to send AUTH LOGIN command. Error: {0}',
+   'SMTPAuthUsername'     => 'Failed to authenticate username. Error: {0}',
+   'SMTPAuthPassword'     => 'Failed to authenticate password. Error: {0}',
+   'SMTPDataFailure'      => 'Unable to send data: {0}',
+   'exitStatus'           => 'Exit status code: {0}',
+];
diff --git a/system/Mailer/Exceptions/MailerException.php b/system/Mailer/Exceptions/MailerException.php
new file mode 100644
index 000000000000..eb1a232aab17
--- /dev/null
+++ b/system/Mailer/Exceptions/MailerException.php
@@ -0,0 +1,97 @@
+<?php
+
+/**
+ * This file is part of the CodeIgniter 4 framework.
+ *
+ * (c) CodeIgniter Foundation <admin@codeigniter.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace CodeIgniter\Mailer\Exceptions;
+
+use CodeIgniter\Exceptions\FrameworkException;
+
+class MailerException extends FrameworkException
+{
+	public static function forAttachmentMissing(string $file = null)
+	{
+		return new static(lang('Mailer.attachmentMissing', [$file]));
+	}
+
+	public static function forAttachmentUnreadable(string $file = null)
+	{
+		return new static(lang('Mailer.attachmentUnreadable', [$file]));
+	}
+
+	public static function forMustBeArray()
+	{
+		return new static(lang('Mailer.mustBeArray', []));
+	}
+
+	public static function forInvalidAddress(string $value = null)
+	{
+		return new static(lang('Mailer.invalidAddress', [$value]));
+	}
+
+	public static function forInvalidProtocol(string $value = null)
+	{
+		return new static(lang('Mailer.invalidProtocolRequested', [$value]));
+	}
+
+	public static function forNoFrom()
+	{
+		return new static(lang('Mailer.noFrom', []));
+	}
+
+	public static function forNoRecipients()
+	{
+		return new static(lang('Mailer.noRecipients', []));
+	}
+
+	public static function forSendFailure(string $protocol = '?')
+	{
+		return new static(lang('Mailer.SendFailure', [$protocol]));
+	}
+
+	public static function forNosocket(string $status = '?')
+	{
+		return new static(lang('Mailer.exitStatus', [$status]) . lang('Mailer.nosocket', []));
+	}
+
+	public static function forNoHostname()
+	{
+		return new static(lang('Mailer.noHostname', []));
+	}
+
+	public static function forSMTPError(string $reply = '?')
+	{
+		return new static(lang('Mailer.SMTPError', [$reply]));
+	}
+
+	public static function forNoSMTPAuth()
+	{
+		return new static(lang('Mailer.noSMTPAuth', []));
+	}
+
+	public static function forFailedSMTPLogin(string $reply = '?')
+	{
+		return new static(lang('Mailer.failedSMTPLogin', [$reply]));
+	}
+
+	public static function forSMTPAuthUsername(string $reply = '?')
+	{
+		return new static(lang('Mailer.SMTPAuthUsername', [$reply]));
+	}
+
+	public static function forSMTPAuthPassword(string $reply = '?')
+	{
+		return new static(lang('Mailer.SMTPAuthPassword', [$reply]));
+	}
+
+	public static function forSMTPDataFailure(string $data = '?')
+	{
+		return new static(lang('Mailer.SMTPDataFailure', [$data]));
+	}
+}
diff --git a/system/Mailer/Handlers/BaseHandler.php b/system/Mailer/Handlers/BaseHandler.php
new file mode 100644
index 000000000000..8e25f038471e
--- /dev/null
+++ b/system/Mailer/Handlers/BaseHandler.php
@@ -0,0 +1,1676 @@
+<?php
+
+namespace CodeIgniter\Mailer\Handlers;
+
+/**
+ * CodeIgniter
+ *
+ * An open source application development framework for PHP
+ *
+ * This content is released under the MIT License (MIT)
+ *
+ * Copyright (c) 2014 - 2018, British Columbia Institute of Technology
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ * @package    CodeIgniter
+ * @author     EllisLab Dev Team
+ * @copyright  Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
+ * @copyright  Copyright (c) 2014 - 2018, British Columbia Institute of Technology (http://bcit.ca/)
+ * @license    http://opensource.org/licenses/MIT    MIT License
+ * @link       https://codeigniter.com
+ * @since      Version 1.0.0
+ * @filesource
+ */
+
+use CodeIgniter\Mailer\Exceptions\MailerException;
+use CodeIgniter\Mailer\MailerInterface;
+use CodeIgniter\Mailer\Message;
+use Config\Mimes;
+use Psr\Log\LoggerAwareTrait;
+use Psr\Log\LoggerInterface;
+
+/**
+ * CodeIgniter Mailer Class
+ *
+ * Permits email to be sent using Mail, Sendmail, or SMTP.
+ *
+ * @package    CodeIgniter
+ * @subpackage Libraries
+ * @category   Libraries
+ * @author     EllisLab Dev Team
+ * @link       https://codeigniter.com/user_guide/libraries/email.html
+ */
+class BaseHandler implements MailerInterface
+{
+
+	public $protocol = 'none';
+
+	/**
+	 * Message format.
+	 *
+	 * @var string 'text' or 'html'
+	 */
+	public $mailType = 'text';
+
+	/**
+	 * Character set (default: utf-8)
+	 *
+	 * @var string
+	 */
+	public $charset = 'utf-8';
+
+	/**
+	 * Alternative message (for HTML messages only)
+	 *
+	 * @var string
+	 */
+	public $altMessage = '';
+
+	/**
+	 * Whether to validate e-mail addresses.
+	 *
+	 * @var boolean
+	 */
+	public $validate = true;
+
+	/**
+	 * X-Priority header value.
+	 *
+	 * @var integer 1-5
+	 */
+	public $priority = 3;            // Default priority (1 - 5)
+
+	/**
+	 * Newline character sequence.
+	 * Use "\r\n" to comply with RFC 822.
+	 *
+	 * @link http://www.ietf.org/rfc/rfc822.txt
+	 * @var  string "\r\n" or "\n"
+	 */
+	public $newline = "\n";            // Default newline. "\r\n" or "\n" (Use "\r\n" to comply with RFC 822)
+
+	/**
+	 * CRLF character sequence
+	 *
+	 * RFC 2045 specifies that for 'quoted-printable' encoding,
+	 * "\r\n" must be used. However, it appears that some servers
+	 * (even on the receiving end) don't handle it properly and
+	 * switching to "\n", while improper, is the only solution
+	 * that seems to work for all environments.
+	 *
+	 * @link http://www.ietf.org/rfc/rfc822.txt
+	 * @var  string
+	 */
+	public $CRLF = "\n";
+
+	/**
+	 * Whether to use Delivery Status Notification.
+	 *
+	 * @var boolean
+	 */
+	public $DSN = false;
+
+	/**
+	 * Whether to send multipart alternatives.
+	 * Yahoo! doesn't seem to like these.
+	 *
+	 * @var boolean
+	 */
+	public $sendMultipart = true;
+
+	/**
+	 * Whether to send messages to BCC recipients in batches.
+	 *
+	 * @var boolean
+	 */
+	public $BCCBatchMode = false;
+
+	/**
+	 * BCC Batch max number size.
+	 *
+	 * @see self::$BCCBatchMode
+	 * @var integer
+	 */
+	public $BCCBatchSize = 200;
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Subject header
+	 *
+	 * @var string
+	 */
+	protected $subject = '';
+
+	/**
+	 * Message body
+	 *
+	 * @var string
+	 */
+	protected $body = '';
+
+	/**
+	 * Final message body to be sent.
+	 *
+	 * @var string
+	 */
+	protected $finalBody = '';
+
+	/**
+	 * Final headers to send
+	 *
+	 * @var string
+	 */
+	protected $headerStr = '';
+
+	/**
+	 * SMTP Connection socket placeholder
+	 *
+	 * @var resource
+	 */
+	protected $SMTPConnect = '';
+
+	/**
+	 * Mail encoding
+	 *
+	 * @var string '8bit' or '7bit'
+	 */
+	protected $encoding = '8bit';
+
+	/**
+	 * Whether to send a Reply-To header
+	 *
+	 * @var boolean
+	 */
+	protected $replyToFlag = false;
+
+	/**
+	 * Debug messages
+	 *
+	 * @see self::printDebugger()
+	 * @var array
+	 */
+	protected $debugMessage = [];
+
+	/**
+	 * Recipients
+	 *
+	 * @var array
+	 */
+	protected $recipients = [];
+
+	/**
+	 * CC Recipients
+	 *
+	 * @var array
+	 */
+	protected $CCArray = [];
+
+	/**
+	 * BCC Recipients
+	 *
+	 * @var array
+	 */
+	protected $BCCArray = [];
+
+	/**
+	 * Message headers
+	 *
+	 * @var array
+	 */
+	protected $headers = [];
+
+	/**
+	 * Attachment data
+	 *
+	 * @var array
+	 */
+	protected $attachments = [];
+
+	/**
+	 * Valid $protocol values
+	 *
+	 * @see self::$protocol
+	 * @var array
+	 */
+	protected $protocols = [
+		'mail',
+		'sendmail',
+		'smtp',
+	];
+
+	/**
+	 * Base charsets
+	 *
+	 * Character sets valid for 7-bit encoding,
+	 * excluding language suffix.
+	 *
+	 * @var array
+	 */
+	protected $baseCharsets = [
+		'us-ascii',
+		'iso-2022-',
+	];
+
+	/**
+	 * Bit depths
+	 *
+	 * Valid mail encodings
+	 *
+	 * @see self::$encoding
+	 * @var array
+	 */
+	protected $bitDepths = [
+		'7bit',
+		'8bit',
+	];
+
+	/**
+	 * $priority translations
+	 *
+	 * Actual values to send with the X-Priority header
+	 *
+	 * @var array
+	 */
+	protected $priorities = [
+		1 => '1 (Highest)',
+		2 => '2 (High)',
+		3 => '3 (Normal)',
+		4 => '4 (Low)',
+		5 => '5 (Lowest)',
+	];
+
+	/**
+	 * mbstring.func_overload flag
+	 *
+	 * @var boolean
+	 */
+	protected static $func_overload;
+
+	/**
+	 * Logger instance to record error messages and awarnings.
+	 *
+	 * @var \PSR\Log\LoggerInterface
+	 */
+	protected $logger;
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Constructor - Sets Preferences
+	 *
+	 * The constructor can be passed an array of config values
+	 *
+	 * @param array|null $config
+	 */
+	public function __construct($config = null)
+	{
+		$this->initialize($config);
+
+		log_message('info', 'Mailer Class Initialized');
+	}
+
+	public function getProtocol() : string
+	{
+		return $this->protocol;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Initialize preferences
+	 *
+	 * @param array|\Config\Mailer $config
+	 *
+	 * @return $this
+	 */
+	public function initialize($config)
+	{
+		$this->clear();
+
+		if ($config instanceof \Config\Mailer)
+		{
+			$config = get_object_vars($config);
+		}
+
+		foreach (get_class_vars(get_class($this)) as $key => $value)
+		{
+			if (property_exists($this, $key) && isset($config[$key]))
+			{
+				$method = 'set' . ucfirst($key);
+
+				if (method_exists($this, $method))
+				{
+					$this->$method($config[$key]);
+				}
+			}
+		}
+
+		$this->charset  = strtoupper($this->charset);
+		$this->SMTPAuth = isset($this->SMTPUser[0], $this->SMTPPass[0]);
+
+		return $this;
+	}
+
+	public function setLogger(LoggerInterface $logger)
+	{
+		$this->logger = $logger;
+	}
+	//--------------------------------------------------------------------
+
+	/**
+	 * Initialize the Data
+	 *
+	 * @param boolean $clearAttachments
+	 *
+	 * @return $this
+	 */
+	public function clear($clearAttachments = false)
+	{
+		$this->subject      = '';
+		$this->body         = '';
+		$this->finalBody    = '';
+		$this->headerStr    = '';
+		$this->replyToFlag  = false;
+		$this->recipients   = [];
+		$this->CCArray      = [];
+		$this->BCCArray     = [];
+		$this->headers      = [];
+		$this->debugMessage = [];
+
+		$this->setHeader('Date', $this->setDate());
+
+		if ($clearAttachments !== false)
+		{
+			$this->attachments = [];
+		}
+
+		return $this;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Build final headers
+	 */
+	protected function buildHeaders()
+	{
+		$this->setHeader('User-Agent', $this->userAgent);
+		$this->setHeader('X-Sender', $this->cleanEmail($this->headers['From']));
+		$this->setHeader('X-Mailer', $this->userAgent);
+		$this->setHeader('X-Priority', $this->priorities[$this->priority]);
+		$this->setHeader('Message-ID', $this->getMessageID());
+		$this->setHeader('Mime-Version', '1.0');
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Write Headers as a string
+	 */
+	protected function writeHeaders()
+	{
+		if ($this->protocol === 'mail')
+		{
+			if (isset($this->headers['Subject']))
+			{
+				$this->subject = $this->headers['Subject'];
+				unset($this->headers['Subject']);
+			}
+		}
+
+		reset($this->headers);
+		$this->headerStr = '';
+
+		foreach ($this->headers as $key => $val)
+		{
+			$val = trim($val);
+
+			if ($val !== '')
+			{
+				$this->headerStr .= $key . ': ' . $val . $this->newline;
+			}
+		}
+
+		if ($this->getProtocol() === 'mail')
+		{
+			$this->headerStr = rtrim($this->headerStr);
+		}
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Build Final Body and attachments
+	 */
+	protected function buildMessage()
+	{
+		if ($this->wordWrap === true && $this->mailType !== 'html')
+		{
+			$this->body = $this->wordWrap($this->body);
+		}
+
+		$this->writeHeaders();
+
+		$hdr  = ($this->getProtocol() === 'mail') ? $this->newline : '';
+		$body = '';
+
+		switch ($this->getContentType())
+		{
+			case 'plain':
+
+				$hdr .= 'Content-Type: text/plain; charset=' . $this->charset . $this->newline
+						. 'Content-Transfer-Encoding: ' . $this->getEncoding();
+
+				if ($this->getProtocol() === 'mail')
+				{
+					$this->headerStr .= $hdr;
+					$this->finalBody  = $this->body;
+				}
+				else
+				{
+					$this->finalBody = $hdr . $this->newline . $this->newline . $this->body;
+				}
+
+				return;
+
+			case 'html':
+
+				if ($this->sendMultipart === false)
+				{
+					$hdr .= 'Content-Type: text/html; charset=' . $this->charset . $this->newline
+							. 'Content-Transfer-Encoding: quoted-printable';
+				}
+				else
+				{
+					$boundary = uniqid('B_ALT_', true);
+					$hdr     .= 'Content-Type: multipart/alternative; boundary="' . $boundary . '"';
+
+					$body .= $this->getMimeMessage() . $this->newline . $this->newline
+							. '--' . $boundary . $this->newline
+							. 'Content-Type: text/plain; charset=' . $this->charset . $this->newline
+							. 'Content-Transfer-Encoding: ' . $this->getEncoding() . $this->newline . $this->newline
+							. $this->getAltMessage() . $this->newline . $this->newline
+							. '--' . $boundary . $this->newline
+							. 'Content-Type: text/html; charset=' . $this->charset . $this->newline
+							. 'Content-Transfer-Encoding: quoted-printable' . $this->newline . $this->newline;
+				}
+
+				$this->finalBody = $body . $this->prepQuotedPrintable($this->body) . $this->newline . $this->newline;
+
+				if ($this->getProtocol() === 'mail')
+				{
+					$this->headerStr .= $hdr;
+				}
+				else
+				{
+					$this->finalBody = $hdr . $this->newline . $this->newline . $this->finalBody;
+				}
+
+				if ($this->sendMultipart !== false)
+				{
+					$this->finalBody .= '--' . $boundary . '--';
+				}
+
+				return;
+
+			case 'plain-attach':
+
+				$boundary = uniqid('B_ATC_', true);
+				$hdr     .= 'Content-Type: multipart/mixed; boundary="' . $boundary . '"';
+
+				if ($this->getProtocol() === 'mail')
+				{
+					$this->headerStr .= $hdr;
+				}
+
+				$body .= $this->getMimeMessage() . $this->newline
+						. $this->newline
+						. '--' . $boundary . $this->newline
+						. 'Content-Type: text/plain; charset=' . $this->charset . $this->newline
+						. 'Content-Transfer-Encoding: ' . $this->getEncoding() . $this->newline
+						. $this->newline
+						. $this->body . $this->newline . $this->newline;
+
+				$this->appendAttachments($body, $boundary);
+
+				break;
+			case 'html-attach':
+
+				$alt_boundary  = uniqid('B_ALT_', true);
+				$last_boundary = null;
+
+				if ($this->attachmentsHaveMultipart('mixed'))
+				{
+					$atc_boundary  = uniqid('B_ATC_', true);
+					$hdr          .= 'Content-Type: multipart/mixed; boundary="' . $atc_boundary . '"';
+					$last_boundary = $atc_boundary;
+				}
+
+				if ($this->attachmentsHaveMultipart('related'))
+				{
+					$rel_boundary        = uniqid('B_REL_', true);
+					$rel_boundary_header = 'Content-Type: multipart/related; boundary="' . $rel_boundary . '"';
+
+					if (isset($last_boundary))
+					{
+						$body .= '--' . $last_boundary . $this->newline . $rel_boundary_header;
+					}
+					else
+					{
+						$hdr .= $rel_boundary_header;
+					}
+
+					$last_boundary = $rel_boundary;
+				}
+
+				if ($this->getProtocol() === 'mail')
+				{
+					$this->headerStr .= $hdr;
+				}
+
+				static::strlen($body) && $body .= $this->newline . $this->newline;
+				$body                          .= $this->getMimeMessage() . $this->newline . $this->newline
+						. '--' . $last_boundary . $this->newline
+						. 'Content-Type: multipart/alternative; boundary="' . $alt_boundary . '"' . $this->newline . $this->newline
+						. '--' . $alt_boundary . $this->newline
+						. 'Content-Type: text/plain; charset=' . $this->charset . $this->newline
+						. 'Content-Transfer-Encoding: ' . $this->getEncoding() . $this->newline . $this->newline
+						. $this->getAltMessage() . $this->newline . $this->newline
+						. '--' . $alt_boundary . $this->newline
+						. 'Content-Type: text/html; charset=' . $this->charset . $this->newline
+						. 'Content-Transfer-Encoding: quoted-printable' . $this->newline . $this->newline
+						. $this->prepQuotedPrintable($this->body) . $this->newline . $this->newline
+						. '--' . $alt_boundary . '--' . $this->newline . $this->newline;
+
+				if (! empty($rel_boundary))
+				{
+					$body .= $this->newline . $this->newline;
+					$this->appendAttachments($body, $rel_boundary, 'related');
+				}
+
+				// multipart/mixed attachments
+				if (! empty($atc_boundary))
+				{
+					$body .= $this->newline . $this->newline;
+					$this->appendAttachments($body, $atc_boundary, 'mixed');
+				}
+
+				break;
+		}
+
+		$this->finalBody = ($this->getProtocol() === 'mail') ? $body : $hdr . $this->newline . $this->newline . $body;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Prepares attachment string
+	 *
+	 * @param string      &$body     Message body to append to
+	 * @param string      $boundary  Multipart boundary
+	 * @param string|null $multipart When provided, only attachments of this type will be processed
+	 *
+	 * @return string
+	 */
+	protected function appendAttachments(&$body, $boundary, $multipart = null)
+	{
+		for ($i = 0, $c = count($this->attachments); $i < $c; $i ++)
+		{
+			if (isset($multipart) && $this->attachments[$i]['multipart'] !== $multipart)
+			{
+				continue;
+			}
+
+			$name = isset($this->attachments[$i]['name'][1]) ? $this->attachments[$i]['name'][1] : basename($this->attachments[$i]['name'][0]);
+
+			$body .= '--' . $boundary . $this->newline
+					. 'Content-Type: ' . $this->attachments[$i]['type'] . '; name="' . $name . '"' . $this->newline
+					. 'Content-Disposition: ' . $this->attachments[$i]['disposition'] . ';' . $this->newline
+					. 'Content-Transfer-Encoding: base64' . $this->newline
+					. (empty($this->attachments[$i]['cid']) ? '' : 'Content-ID: <' . $this->attachments[$i]['cid'] . '>' . $this->newline)
+					. $this->newline
+					. $this->attachments[$i]['content'] . $this->newline;
+		}
+
+		// $name won't be set if no attachments were appended,
+		// and therefore a boundary wouldn't be necessary
+		empty($name) || $body .= '--' . $boundary . '--';
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Prep Quoted Printable
+	 *
+	 * Prepares string for Quoted-Printable Content-Transfer-Encoding
+	 * Refer to RFC 2045 http://www.ietf.org/rfc/rfc2045.txt
+	 *
+	 * @param string $str
+	 *
+	 * @return string
+	 */
+	protected function prepQuotedPrintable($str)
+	{
+		// ASCII code numbers for "safe" characters that can always be
+		// used literally, without encoding, as described in RFC 2049.
+		// http://www.ietf.org/rfc/rfc2049.txt
+		static $ascii_safe_chars = [
+			// ' (  )   +   ,   -   .   /   :   =   ?
+			39,
+			40,
+			41,
+			43,
+			44,
+			45,
+			46,
+			47,
+			58,
+			61,
+			63,
+			// numbers
+			48,
+			49,
+			50,
+			51,
+			52,
+			53,
+			54,
+			55,
+			56,
+			57,
+			// upper-case letters
+			65,
+			66,
+			67,
+			68,
+			69,
+			70,
+			71,
+			72,
+			73,
+			74,
+			75,
+			76,
+			77,
+			78,
+			79,
+			80,
+			81,
+			82,
+			83,
+			84,
+			85,
+			86,
+			87,
+			88,
+			89,
+			90,
+			// lower-case letters
+			97,
+			98,
+			99,
+			100,
+			101,
+			102,
+			103,
+			104,
+			105,
+			106,
+			107,
+			108,
+			109,
+			110,
+			111,
+			112,
+			113,
+			114,
+			115,
+			116,
+			117,
+			118,
+			119,
+			120,
+			121,
+			122,
+		];
+
+		// We are intentionally wrapping so mail servers will encode characters
+		// properly and MUAs will behave, so {unwrap} must go!
+		$str = str_replace(['{unwrap}', '{/unwrap}'], '', $str);
+
+		// RFC 2045 specifies CRLF as "\r\n".
+		// However, many developers choose to override that and violate
+		// the RFC rules due to (apparently) a bug in MS Exchange,
+		// which only works with "\n".
+		if ($this->CRLF === "\r\n")
+		{
+			return quoted_printable_encode($str);
+		}
+
+		// Reduce multiple spaces & remove nulls
+		$str = preg_replace(['| +|', '/\x00+/'], [' ', ''], $str);
+
+		// Standardize newlines
+		if (strpos($str, "\r") !== false)
+		{
+			$str = str_replace(["\r\n", "\r"], "\n", $str);
+		}
+
+		$escape = '=';
+		$output = '';
+
+		foreach (explode("\n", $str) as $line)
+		{
+			$length = static::strlen($line);
+			$temp   = '';
+
+			// Loop through each character in the line to add soft-wrap
+			// characters at the end of a line " =\r\n" and add the newly
+			// processed line(s) to the output (see comment on $crlf class property)
+			for ($i = 0; $i < $length; $i ++)
+			{
+				// Grab the next character
+				$char  = $line[$i];
+				$ascii = ord($char);
+
+				// Convert spaces and tabs but only if it's the end of the line
+				if ($ascii === 32 || $ascii === 9)
+				{
+					if ($i === ($length - 1))
+					{
+						$char = $escape . sprintf('%02s', dechex($ascii));
+					}
+				}
+				// DO NOT move this below the $ascii_safe_chars line!
+				//
+				// = (equals) signs are allowed by RFC2049, but must be encoded
+				// as they are the encoding delimiter!
+				elseif ($ascii === 61)
+				{
+					$char = $escape . strtoupper(sprintf('%02s', dechex($ascii)));  // =3D
+				}
+				elseif (! in_array($ascii, $ascii_safe_chars, true))
+				{
+					$char = $escape . strtoupper(sprintf('%02s', dechex($ascii)));
+				}
+
+				// If we're at the character limit, add the line to the output,
+				// reset our temp variable, and keep on chuggin'
+				if ((static::strlen($temp) + static::strlen($char)) >= 76)
+				{
+					$output .= $temp . $escape . $this->CRLF;
+					$temp    = '';
+				}
+
+				// Add the character to our temporary line
+				$temp .= $char;
+			}
+
+			// Add our completed line to the output
+			$output .= $temp . $this->CRLF;
+		}
+
+		// get rid of extra CRLF tacked onto the end
+		return static::substr($output, 0, static::strlen($this->CRLF) * -1);
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Send a Message
+	 *
+	 * @param boolean $autoClear
+	 * @param boolean $reallySend
+	 *
+	 * @return boolean
+	 */
+	public function send(Message $message, bool $autoClear = true, bool $reallySend = true)
+	{
+		if (! isset($this->headers['From']) && ! empty($this->fromEmail))
+		{
+			$this->setFrom($this->fromEmail, $this->fromName);
+		}
+
+		if (! isset($this->headers['From']))
+		{
+				throw MailerException::forNoFrom();
+		}
+
+		if ($this->replyToFlag === false)
+		{
+			$this->setReplyTo($this->headers['From']);
+		}
+
+		if (empty($this->recipients) && ! isset($this->headers['To']) && empty($this->BCCArray) && ! isset($this->headers['Bcc']) && ! isset($this->headers['Cc'])
+		)
+		{
+				throw MailerException::forNoRecipients();
+		}
+
+		$this->buildHeaders();
+
+		if ($this->BCCBatchMode && count($this->BCCArray) > $this->BCCBatchSize)
+		{
+			$this->batchBCCSend();
+
+			if ($autoClear)
+			{
+				$this->clear();
+			}
+
+			return true;
+		}
+
+		$this->buildMessage();
+		$result = $this->spoolEmail();
+
+		if ($result && $autoClear)
+		{
+			$this->clear();
+		}
+
+		return $result;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Batch Bcc Send. Sends groups of BCCs in batches
+	 */
+	public function batchBCCSend()
+	{
+		$float = $this->BCCBatchSize - 1;
+		$set   = '';
+		$chunk = [];
+
+		for ($i = 0, $c = count($this->BCCArray); $i < $c; $i ++)
+		{
+			if (isset($this->BCCArray[$i]))
+			{
+				$set .= ', ' . $this->BCCArray[$i];
+			}
+
+			if ($i === $float)
+			{
+				$chunk[] = static::substr($set, 1);
+				$float  += $this->BCCBatchSize;
+				$set     = '';
+			}
+
+			if ($i === $c - 1)
+			{
+				$chunk[] = static::substr($set, 1);
+			}
+		}
+
+		for ($i = 0, $c = count($chunk); $i < $c; $i ++)
+		{
+			unset($this->headers['Bcc']);
+
+			$bcc = $this->cleanEmail($this->stringToArray($chunk[$i]));
+
+			if ($this->protocol !== 'smtp')
+			{
+				$this->setHeader('Bcc', implode(', ', $bcc));
+			}
+			else
+			{
+				$this->BCCArray = $bcc;
+			}
+
+			$this->buildMessage();
+			$this->spoolEmail();
+		}
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Unwrap special elements
+	 */
+	protected function unwrapSpecials()
+	{
+		$this->finalBody = preg_replace_callback(
+				'/\{unwrap\}(.*?)\{\/unwrap\}/si', [
+					$this,
+					'removeNLCallback',
+				], $this->finalBody
+		);
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Strip line-breaks via callback
+	 *
+	 * @param string $matches
+	 *
+	 * @return string
+	 */
+	protected function removeNLCallback($matches)
+	{
+		if (strpos($matches[1], "\r") !== false || strpos($matches[1], "\n") !== false)
+		{
+			$matches[1] = str_replace(["\r\n", "\r", "\n"], '', $matches[1]);
+		}
+
+		return $matches[1];
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Spool mail to the mail server
+	 *
+	 * @return boolean
+	 */
+	protected function spoolEmail()
+	{
+		$this->unwrapSpecials();
+
+		$protocol = $this->getProtocol();
+		$method   = 'sendWith' . ucfirst($protocol);
+		try
+		{
+			$success = $this->$method();
+		}
+		catch (\ErrorException $e)
+		{
+			$success = false;
+			$this->logger->error('Mailer: ' . $method . ' throwed ' . $e->getMessage());
+		}
+
+		if (! $success)
+		{
+				throw MailerException::forSendFailure($protocol === 'mail' ? 'PHPMail' : ucfirst($protocol));
+		}
+
+		$this->setErrorMessage(lang('Mailer.sent', [$protocol]));
+
+		return true;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Validate email for shell
+	 *
+	 * Applies stricter, shell-safe validation to email addresses.
+	 * Introduced to prevent RCE via sendmail's -f option.
+	 *
+	 * @see     https://github.com/codeigniter4/CodeIgniter/issues/4963
+	 * @see     https://gist.github.com/Zenexer/40d02da5e07f151adeaeeaa11af9ab36
+	 * @license https://creativecommons.org/publicdomain/zero/1.0/    CC0 1.0, Public Domain
+	 *
+	 * Credits for the base concept go to Paul Buonopane <paul@namepros.com>
+	 *
+	 * @param string &$email
+	 *
+	 * @return boolean
+	 */
+	protected function validateEmailForShell(&$email)
+	{
+		if (function_exists('idn_to_ascii') && $atpos = strpos($email, '@'))
+		{
+			$email = static::substr($email, 0, ++ $atpos) . idn_to_ascii(
+							static::substr($email, $atpos), 0, INTL_IDNA_VARIANT_UTS46
+			);
+		}
+
+		return (filter_var($email, FILTER_VALIDATE_EMAIL) === $email && preg_match('#\A[a-z0-9._+-]+@[a-z0-9.-]{1,253}\z#i', $email));
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Send using mail()
+	 *
+	 * @return boolean
+	 */
+	protected function sendWithMail()
+	{
+		if (is_array($this->recipients))
+		{
+			$this->recipients = implode(', ', $this->recipients);
+		}
+
+		// _validate_email_for_shell() below accepts by reference,
+		// so this needs to be assigned to a variable
+		$from = $this->cleanEmail($this->headers['Return-Path']);
+
+		if (! $this->validateEmailForShell($from))
+		{
+			return mail($this->recipients, $this->subject, $this->finalBody, $this->headerStr);
+		}
+
+		// most documentation of sendmail using the "-f" flag lacks a space after it, however
+		// we've encountered servers that seem to require it to be in place.
+		return mail($this->recipients, $this->subject, $this->finalBody, $this->headerStr, '-f ' . $from);
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Send using Sendmail
+	 *
+	 * @return boolean
+	 */
+	protected function sendWithSendmail()
+	{
+		// _validate_email_for_shell() below accepts by reference,
+		// so this needs to be assigned to a variable
+		$from = $this->cleanEmail($this->headers['From']);
+		if ($this->validateEmailForShell($from))
+		{
+			$from = '-f ' . $from;
+		}
+		else
+		{
+			$from = '';
+		}
+
+		// is popen() enabled?
+		if (! function_usable('popen') || false === ($fp = @popen($this->mailPath . ' -oi ' . $from . ' -t', 'w')))
+		{
+			// server probably has popen disabled, so nothing we can do to get a verbose error.
+			return false;
+		}
+
+		fputs($fp, $this->headerStr);
+		fputs($fp, $this->finalBody);
+
+		$status = pclose($fp);
+
+		if ($status !== 0)
+		{
+				throw MailerException::forNosocket($status);
+		}
+
+		return true;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Send using SMTP
+	 *
+	 * @return boolean
+	 */
+	protected function sendWithSmtp()
+	{
+		if ($this->SMTPHost === '')
+		{
+				throw MailerException::forNoHostname();
+		}
+
+		if (! $this->SMTPConnect() || ! $this->SMTPAuthenticate())
+		{
+			return false;
+		}
+
+		if (! $this->sendCommand('from', $this->cleanFrameworkException($this->headers['From'])))
+		{
+			$this->SMTPEnd();
+
+			return false;
+		}
+
+		foreach ($this->recipients as $val)
+		{
+			if (! $this->sendCommand('to', $val))
+			{
+				$this->SMTPEnd();
+
+				return false;
+			}
+		}
+
+		foreach ($this->CCArray as $val)
+		{
+			if ($val !== '' && ! $this->sendCommand('to', $val))
+			{
+				$this->SMTPEnd();
+
+				return false;
+			}
+		}
+
+		foreach ($this->BCCArray as $val)
+		{
+			if ($val !== '' && ! $this->sendCommand('to', $val))
+			{
+				$this->SMTPEnd();
+
+				return false;
+			}
+		}
+
+		if (! $this->sendCommand('data'))
+		{
+			$this->SMTPEnd();
+
+			return false;
+		}
+
+		// perform dot transformation on any lines that begin with a dot
+		$this->sendData($this->headerStr . preg_replace('/^\./m', '..$1', $this->finalBody));
+
+		$this->sendData('.');
+		$reply = $this->getSMTPData();
+		$this->setErrorMessage($reply);
+
+		$this->SMTPEnd();
+
+		if (strpos($reply, '250') !== 0)
+		{
+				throw FrameworkExceptionException::forSMTPError($reply);
+		}
+
+		return true;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * SMTP End
+	 *
+	 * Shortcut to send RSET or QUIT depending on keep-alive
+	 */
+	protected function SMTPEnd()
+	{
+		$this->sendCommand($this->SMTPKeepAlive ? 'reset' : 'quit');
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * SMTP Connect
+	 *
+	 * @return string
+	 */
+	protected function SMTPConnect()
+	{
+		if (is_resource($this->SMTPConnect))
+		{
+			return true;
+		}
+
+		$ssl = ($this->SMTPCrypto === 'ssl') ? 'ssl://' : '';
+
+		$this->SMTPConnect = fsockopen(
+				$ssl . $this->SMTPHost, $this->SMTPPort, $errno, $errstr, $this->SMTPTimeout
+		);
+
+		if (! is_resource($this->SMTPConnect))
+		{
+				throw FrameworkExceptionException::forSMTPError($errno . ' ' . $errstr);
+		}
+
+		stream_set_timeout($this->SMTPConnect, $this->SMTPTimeout);
+		$this->setErrorMessage($this->getSMTPData());
+
+		if ($this->SMTPCrypto === 'tls')
+		{
+			$this->sendCommand('hello');
+			$this->sendCommand('starttls');
+
+			$crypto = stream_socket_enable_crypto($this->SMTPConnect, true, STREAM_CRYPTO_METHOD_TLS_CLIENT);
+
+			if ($crypto !== true)
+			{
+				throw FrameworkExceptionException::forSMTPError($this->getSMTPData());
+			}
+		}
+
+		return $this->sendCommand('hello');
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Send SMTP command
+	 *
+	 * @param string $cmd
+	 * @param string $data
+	 *
+	 * @return boolean
+	 */
+	protected function sendCommand($cmd, $data = '')
+	{
+		switch ($cmd)
+		{
+			case 'hello':
+				if ($this->SMTPAuth || $this->getEncoding() === '8bit')
+				{
+					$this->sendData('EHLO ' . $this->getHostname());
+				}
+				else
+				{
+					$this->sendData('HELO ' . $this->getHostname());
+				}
+
+				$resp = 250;
+				break;
+			case 'starttls':
+				$this->sendData('STARTTLS');
+				$resp = 220;
+				break;
+			case 'from':
+				$this->sendData('MAIL FROM:<' . $data . '>');
+				$resp = 250;
+				break;
+			case 'to':
+				if ($this->DSN)
+				{
+					$this->sendData('RCPT TO:<' . $data . '> NOTIFY=SUCCESS,DELAY,FAILURE ORCPT=rfc822;' . $data);
+				}
+				else
+				{
+					$this->sendData('RCPT TO:<' . $data . '>');
+				}
+				$resp = 250;
+				break;
+			case 'data':
+				$this->sendData('DATA');
+				$resp = 354;
+				break;
+			case 'reset':
+				$this->sendData('RSET');
+				$resp = 250;
+				break;
+			case 'quit':
+				$this->sendData('QUIT');
+				$resp = 221;
+				break;
+		}
+
+		$reply = $this->getSMTPData();
+
+		$this->debugMessage[] = '<pre>' . $cmd . ': ' . $reply . '</pre>';
+
+		if ((int) static::substr($reply, 0, 3) !== $resp)
+		{
+				throw FrameworkExceptionException::forSMTPError($reply);
+		}
+
+		if ($cmd === 'quit')
+		{
+			fclose($this->SMTPConnect);
+		}
+
+		return true;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * SMTP Authenticate
+	 *
+	 * @return boolean
+	 */
+	protected function SMTPAuthenticate()
+	{
+		if (! $this->SMTPAuth)
+		{
+			return true;
+		}
+
+		if ($this->SMTPUser === '' && $this->SMTPPass === '')
+		{
+				throw FrameworkExceptionException::forNoSMTPAuth();
+		}
+
+		$this->sendData('AUTH LOGIN');
+		$reply = $this->getSMTPData();
+
+		if (strpos($reply, '503') === 0)    // Already authenticated
+		{
+			return true;
+		}
+		elseif (strpos($reply, '334') !== 0)
+		{
+				throw FrameworkExceptionException::forFailedSMTPLogin($reply);
+		}
+
+		$this->sendData(base64_encode($this->SMTPUser));
+		$reply = $this->getSMTPData();
+
+		if (strpos($reply, '334') !== 0)
+		{
+				throw FrameworkExceptionException::forSMTPAuthUsername($reply);
+		}
+
+		$this->sendData(base64_encode($this->SMTPPass));
+		$reply = $this->getSMTPData();
+
+		if (strpos($reply, '235') !== 0)
+		{
+				throw FrameworkExceptionException::forSMTPAuthPassword($reply);
+		}
+
+		if ($this->SMTPKeepAlive)
+		{
+			$this->SMTPAuth = false;
+		}
+
+		return true;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Send SMTP data
+	 *
+	 * @param string $data
+	 *
+	 * @return boolean
+	 */
+	protected function sendData($data)
+	{
+		$data .= $this->newline;
+		for ($written = $timestamp = 0, $length = static::strlen($data); $written < $length; $written += $result)
+		{
+			if (($result = fwrite($this->SMTPConnect, static::substr($data, $written))) === false)
+			{
+				break;
+			}
+			// See https://bugs.php.net/bug.php?id=39598 and http://php.net/manual/en/function.fwrite.php#96951
+			elseif ($result === 0)
+			{
+				if ($timestamp === 0)
+				{
+					$timestamp = time();
+				}
+				elseif ($timestamp < (time() - $this->SMTPTimeout))
+				{
+					$result = false;
+					break;
+				}
+
+				usleep(250000);
+				continue;
+			}
+			else
+			{
+				$timestamp = 0;
+			}
+		}
+
+		if ($result === false)
+		{
+				throw FrameworkExceptionException::forSMTPDataFailure($data);
+		}
+
+		return true;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Get SMTP data
+	 *
+	 * @return string
+	 */
+	protected function getSMTPData()
+	{
+		$data = '';
+
+		while ($str = fgets($this->SMTPConnect, 512))
+		{
+			$data .= $str;
+
+			if ($str[3] === ' ')
+			{
+				break;
+			}
+		}
+
+		return $data;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Get Hostname
+	 *
+	 * There are only two legal types of hostname - either a fully
+	 * qualified domain name (eg: "mail.example.com") or an IP literal
+	 * (eg: "[1.2.3.4]").
+	 *
+	 * @link https://tools.ietf.org/html/rfc5321#section-2.3.5
+	 * @link http://cbl.abuseat.org/namingproblems.html
+	 *
+	 * @return string
+	 */
+	protected function getHostname()
+	{
+		if (isset($_SERVER['SERVER_NAME']))
+		{
+			return $_SERVER['SERVER_NAME'];
+		}
+
+		return isset($_SERVER['SERVER_ADDR']) ? '[' . $_SERVER['SERVER_ADDR'] . ']' : '[127.0.0.1]';
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Get Debug Message
+	 *
+	 * @param array $include List of raw data chunks to include in the output
+	 *                       Valid options are: 'headers', 'subject', 'body'
+	 *
+	 * @return string
+	 */
+	public function printDebugger($include = ['headers', 'subject', 'body'])
+	{
+		$msg = implode('', $this->debugMessage);
+
+		// Determine which parts of our raw data needs to be printed
+		$raw_data                      = '';
+		is_array($include) || $include = [$include];
+
+		in_array('headers', $include, true) && $raw_data  = htmlspecialchars($this->headerStr) . "\n";
+		in_array('subject', $include, true) && $raw_data .= htmlspecialchars($this->subject) . "\n";
+		in_array('body', $include, true) && $raw_data    .= htmlspecialchars($this->finalBody);
+
+		return $msg . ($raw_data === '' ? '' : '<pre>' . $raw_data . '</pre>');
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Set Message
+	 *
+	 * @param string $msg
+	 */
+	protected function setErrorMessage($msg)
+	{
+		$this->debugMessage[] = $msg . '<br />';
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Mime Types
+	 *
+	 * @param string $ext
+	 *
+	 * @return string
+	 */
+	protected function mimeTypes($ext = '')
+	{
+		$mime = Mimes::guessTypeFromExtension(strtolower($ext));
+
+		return ! empty($mime) ? $mime : 'application/x-unknown-content-type';
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Get the Message ID
+	 *
+	 * @return string
+	 */
+	protected function getMessageID()
+	{
+		$from = str_replace(['>', '<'], '', $this->headers['Return-Path']);
+
+		return '<' . uniqid('', true) . strstr($from, '@') . '>';
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Get Mail Encoding
+	 *
+	 * @return string
+	 */
+	protected function getEncoding()
+	{
+		in_array($this->encoding, $this->bitDepths) || $this->encoding = '8bit';
+
+		foreach ($this->baseCharsets as $charset)
+		{
+			if (strpos($this->charset, $charset) === 0)
+			{
+				$this->encoding = '7bit';
+				break;
+			}
+		}
+
+		return $this->encoding;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Get content type (text/html/attachment)
+	 *
+	 * @return string
+	 */
+	protected function getContentType()
+	{
+		if ($this->mailType === 'html')
+		{
+			return empty($this->attachments) ? 'html' : 'html-attach';
+		}
+		elseif ($this->mailType === 'text' && ! empty($this->attachments))
+		{
+			return 'plain-attach';
+		}
+		else
+		{
+			return 'plain';
+		}
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Mime message
+	 *
+	 * @return string
+	 */
+	protected function getMimeMessage()
+	{
+		return 'This is a multi-part message in MIME format.' . $this->newline . 'Your email application may not support this format.';
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Build alternative plain text message
+	 *
+	 * Provides the raw message for use in plain-text headers of
+	 * HTML-formatted emails.
+	 * If the user hasn't specified his own alternative message
+	 * it creates one by stripping the HTML
+	 *
+	 * @return string
+	 */
+	protected function getAltMessage()
+	{
+		if (! empty($this->altMessage))
+		{
+			return ($this->wordWrap) ? $this->wordWrap($this->altMessage, 76) : $this->altMessage;
+		}
+
+		$body = preg_match('/\<body.*?\>(.*)\<\/body\>/si', $this->body, $match) ? $match[1] : $this->body;
+		$body = str_replace("\t", '', preg_replace('#<!--(.*)--\>#', '', trim(strip_tags($body))));
+
+		for ($i = 20; $i >= 3; $i --)
+		{
+			$body = str_replace(str_repeat("\n", $i), "\n\n", $body);
+		}
+
+		// Reduce multiple spaces
+		$body = preg_replace('| +|', ' ', $body);
+
+		return ($this->wordWrap) ? $this->wordWrap($body, 76) : $body;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Destructor
+	 */
+	public function __destruct()
+	{
+		is_resource($this->SMTPConnect) && $this->sendCommand('quit');
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Byte-safe strlen()
+	 *
+	 * @param string $str
+	 *
+	 * @return integer
+	 */
+	protected static function strlen($str)
+	{
+		return (static::$func_overload) ? mb_strlen($str, '8bit') : strlen($str);
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Byte-safe substr()
+	 *
+	 * @param string       $str
+	 * @param integer      $start
+	 * @param integer|null $length
+	 *
+	 * @return string
+	 */
+	protected static function substr($str, $start, $length = null)
+	{
+		if (static::$func_overload)
+		{
+			return mb_substr($str, $start, $length, '8bit');
+		}
+
+		return isset($length) ? substr($str, $start, $length) : substr($str, $start);
+	}
+
+}
diff --git a/system/Mailer/Handlers/MailHandler.php b/system/Mailer/Handlers/MailHandler.php
new file mode 100644
index 000000000000..3dced67d758b
--- /dev/null
+++ b/system/Mailer/Handlers/MailHandler.php
@@ -0,0 +1,1634 @@
+<?php
+namespace CodeIgniter\Mailer\Handlers;
+
+/**
+ * CodeIgniter
+ *
+ * An open source application development framework for PHP
+ *
+ * This content is released under the MIT License (MIT)
+ *
+ * Copyright (c) 2014 - 2018, British Columbia Institute of Technology
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ * @package    CodeIgniter
+ * @author     EllisLab Dev Team
+ * @copyright  Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
+ * @copyright  Copyright (c) 2014 - 2018, British Columbia Institute of Technology (http://bcit.ca/)
+ * @license    http://opensource.org/licenses/MIT    MIT License
+ * @link       https://codeigniter.com
+ * @since      Version 1.0.0
+ * @filesource
+ */
+
+use CodeIgniter\Mailer\Message;
+use CodeIgniter\Mailer\Exceptions\MailerException;
+use Config\Mimes;
+use Psr\Log\LoggerAwareTrait;
+
+/**
+ * CodeIgniter Mailer Class
+ *
+ * Permits email to be sent using Mail, Sendmail, or SMTP.
+ *
+ * @package    CodeIgniter
+ * @subpackage Libraries
+ * @category   Libraries
+ * @author     EllisLab Dev Team
+ * @link       https://codeigniter.com/user_guide/libraries/email.html
+ */
+class MailHandler extends BaseHandler
+{
+
+	/**
+	 * Message format.
+	 *
+	 * @var string 'text' or 'html'
+	 */
+	public $mailType = 'text';
+
+	/**
+	 * Character set (default: utf-8)
+	 *
+	 * @var string
+	 */
+	public $charset = 'utf-8';
+
+	/**
+	 * Alternative message (for HTML messages only)
+	 *
+	 * @var string
+	 */
+	public $altMessage = '';
+
+	/**
+	 * Whether to validate e-mail addresses.
+	 *
+	 * @var boolean
+	 */
+	public $validate = true;
+
+	/**
+	 * X-Priority header value.
+	 *
+	 * @var integer 1-5
+	 */
+	public $priority = 3;            // Default priority (1 - 5)
+
+	/**
+	 * Newline character sequence.
+	 * Use "\r\n" to comply with RFC 822.
+	 *
+	 * @link http://www.ietf.org/rfc/rfc822.txt
+	 * @var  string "\r\n" or "\n"
+	 */
+	public $newline = "\n";            // Default newline. "\r\n" or "\n" (Use "\r\n" to comply with RFC 822)
+
+	/**
+	 * CRLF character sequence
+	 *
+	 * RFC 2045 specifies that for 'quoted-printable' encoding,
+	 * "\r\n" must be used. However, it appears that some servers
+	 * (even on the receiving end) don't handle it properly and
+	 * switching to "\n", while improper, is the only solution
+	 * that seems to work for all environments.
+	 *
+	 * @link http://www.ietf.org/rfc/rfc822.txt
+	 * @var  string
+	 */
+	public $CRLF = "\n";
+
+	/**
+	 * Whether to use Delivery Status Notification.
+	 *
+	 * @var boolean
+	 */
+	public $DSN = false;
+
+	/**
+	 * Whether to send multipart alternatives.
+	 * Yahoo! doesn't seem to like these.
+	 *
+	 * @var boolean
+	 */
+	public $sendMultipart = true;
+
+	/**
+	 * Whether to send messages to BCC recipients in batches.
+	 *
+	 * @var boolean
+	 */
+	public $BCCBatchMode = false;
+
+	/**
+	 * BCC Batch max number size.
+	 *
+	 * @see self::$BCCBatchMode
+	 * @var integer
+	 */
+	public $BCCBatchSize = 200;
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Subject header
+	 *
+	 * @var string
+	 */
+	protected $subject = '';
+
+	/**
+	 * Message body
+	 *
+	 * @var string
+	 */
+	protected $body = '';
+
+	/**
+	 * Final message body to be sent.
+	 *
+	 * @var string
+	 */
+	protected $finalBody = '';
+
+	/**
+	 * Final headers to send
+	 *
+	 * @var string
+	 */
+	protected $headerStr = '';
+
+	/**
+	 * SMTP Connection socket placeholder
+	 *
+	 * @var resource
+	 */
+	protected $SMTPConnect = '';
+
+	/**
+	 * Mail encoding
+	 *
+	 * @var string '8bit' or '7bit'
+	 */
+	protected $encoding = '8bit';
+
+	/**
+	 * Whether to send a Reply-To header
+	 *
+	 * @var boolean
+	 */
+	protected $replyToFlag = false;
+
+	/**
+	 * Debug messages
+	 *
+	 * @see self::printDebugger()
+	 * @var array
+	 */
+	protected $debugMessage = [];
+
+	/**
+	 * Recipients
+	 *
+	 * @var array
+	 */
+	protected $recipients = [];
+
+	/**
+	 * CC Recipients
+	 *
+	 * @var array
+	 */
+	protected $CCArray = [];
+
+	/**
+	 * BCC Recipients
+	 *
+	 * @var array
+	 */
+	protected $BCCArray = [];
+
+	/**
+	 * Message headers
+	 *
+	 * @var array
+	 */
+	protected $headers = [];
+
+	/**
+	 * Attachment data
+	 *
+	 * @var array
+	 */
+	protected $attachments = [];
+
+	/**
+	 * Valid $protocol values
+	 *
+	 * @see self::$protocol
+	 * @var array
+	 */
+	protected $protocols = [
+		'mail',
+		'sendmail',
+		'smtp',
+	];
+
+	/**
+	 * Base charsets
+	 *
+	 * Character sets valid for 7-bit encoding,
+	 * excluding language suffix.
+	 *
+	 * @var array
+	 */
+	protected $baseCharsets = [
+		'us-ascii',
+		'iso-2022-',
+	];
+
+	/**
+	 * Bit depths
+	 *
+	 * Valid mail encodings
+	 *
+	 * @see self::$encoding
+	 * @var array
+	 */
+	protected $bitDepths = [
+		'7bit',
+		'8bit',
+	];
+
+	/**
+	 * $priority translations
+	 *
+	 * Actual values to send with the X-Priority header
+	 *
+	 * @var array
+	 */
+	protected $priorities = [
+		1 => '1 (Highest)',
+		2 => '2 (High)',
+		3 => '3 (Normal)',
+		4 => '4 (Low)',
+		5 => '5 (Lowest)',
+	];
+
+	/**
+	 * mbstring.func_overload flag
+	 *
+	 * @var boolean
+	 */
+	protected static $func_overload;
+
+	/**
+	 * Logger instance to record error messages and awarnings.
+	 *
+	 * @var \PSR\Log\LoggerInterface
+	 */
+	protected $logger;
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Constructor - Sets Preferences
+	 *
+	 * The constructor can be passed an array of config values
+	 *
+	 * @param array|null $config
+	 */
+	public function __construct($config = null)
+	{
+		$this->protocol = 'mail';
+		$this->initialize($config);
+
+		log_message('info', 'Mailer Class Initialized');
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Initialize preferences
+	 *
+	 * @param array|\Config\Mailer $config
+	 *
+	 * @return $this
+	 */
+	public function initialize($config)
+	{
+		$this->clear();
+
+		if ($config instanceof \Config\Mailer)
+		{
+			$config = get_object_vars($config);
+		}
+
+		foreach (get_class_vars(get_class($this)) as $key => $value)
+		{
+			if (property_exists($this, $key) && isset($config[$key]))
+			{
+				$method = 'set' . ucfirst($key);
+
+				if (method_exists($this, $method))
+				{
+					$this->$method($config[$key]);
+				}
+			}
+		}
+
+		$this->charset  = strtoupper($this->charset);
+		$this->SMTPAuth = isset($this->SMTPUser[0], $this->SMTPPass[0]);
+
+		return $this;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Initialize the Data
+	 *
+	 * @param boolean $clearAttachments
+	 *
+	 * @return $this
+	 */
+	public function clear($clearAttachments = false)
+	{
+		$this->subject      = '';
+		$this->body         = '';
+		$this->finalBody    = '';
+		$this->headerStr    = '';
+		$this->replyToFlag  = false;
+		$this->recipients   = [];
+		$this->CCArray      = [];
+		$this->BCCArray     = [];
+		$this->headers      = [];
+		$this->debugMessage = [];
+
+		//      $this->setHeader('Date', $this->setDate());
+
+		if ($clearAttachments !== false)
+		{
+			$this->attachments = [];
+		}
+
+		return $this;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Build final headers
+	 */
+	protected function buildHeaders()
+	{
+		$this->setHeader('User-Agent', $this->userAgent);
+		$this->setHeader('X-Sender', $this->cleanEmail($this->headers['From']));
+		$this->setHeader('X-Mailer', $this->userAgent);
+		$this->setHeader('X-Priority', $this->priorities[$this->priority]);
+		$this->setHeader('Message-ID', $this->getMessageID());
+		$this->setHeader('Mime-Version', '1.0');
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Write Headers as a string
+	 */
+	protected function writeHeaders()
+	{
+		if ($this->protocol === 'mail')
+		{
+			if (isset($this->headers['Subject']))
+			{
+				$this->subject = $this->headers['Subject'];
+				unset($this->headers['Subject']);
+			}
+		}
+
+		reset($this->headers);
+		$this->headerStr = '';
+
+		foreach ($this->headers as $key => $val)
+		{
+			$val = trim($val);
+
+			if ($val !== '')
+			{
+				$this->headerStr .= $key . ': ' . $val . $this->newline;
+			}
+		}
+
+		if ($this->getProtocol() === 'mail')
+		{
+			$this->headerStr = rtrim($this->headerStr);
+		}
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Build Final Body and attachments
+	 */
+	protected function buildMessage()
+	{
+		if ($this->wordWrap === true && $this->mailType !== 'html')
+		{
+			$this->body = $this->wordWrap($this->body);
+		}
+
+		$this->writeHeaders();
+
+		$hdr  = ($this->getProtocol() === 'mail') ? $this->newline : '';
+		$body = '';
+
+		switch ($this->getContentType())
+		{
+			case 'plain':
+
+				$hdr .= 'Content-Type: text/plain; charset=' . $this->charset . $this->newline
+						. 'Content-Transfer-Encoding: ' . $this->getEncoding();
+
+				if ($this->getProtocol() === 'mail')
+				{
+					$this->headerStr .= $hdr;
+					$this->finalBody  = $this->body;
+				}
+				else
+				{
+					$this->finalBody = $hdr . $this->newline . $this->newline . $this->body;
+				}
+
+				return;
+
+			case 'html':
+
+				if ($this->sendMultipart === false)
+				{
+					$hdr .= 'Content-Type: text/html; charset=' . $this->charset . $this->newline
+							. 'Content-Transfer-Encoding: quoted-printable';
+				}
+				else
+				{
+					$boundary = uniqid('B_ALT_', true);
+					$hdr     .= 'Content-Type: multipart/alternative; boundary="' . $boundary . '"';
+
+					$body .= $this->getMimeMessage() . $this->newline . $this->newline
+							. '--' . $boundary . $this->newline
+							. 'Content-Type: text/plain; charset=' . $this->charset . $this->newline
+							. 'Content-Transfer-Encoding: ' . $this->getEncoding() . $this->newline . $this->newline
+							. $this->getAltMessage() . $this->newline . $this->newline
+							. '--' . $boundary . $this->newline
+							. 'Content-Type: text/html; charset=' . $this->charset . $this->newline
+							. 'Content-Transfer-Encoding: quoted-printable' . $this->newline . $this->newline;
+				}
+
+				$this->finalBody = $body . $this->prepQuotedPrintable($this->body) . $this->newline . $this->newline;
+
+				if ($this->getProtocol() === 'mail')
+				{
+					$this->headerStr .= $hdr;
+				}
+				else
+				{
+					$this->finalBody = $hdr . $this->newline . $this->newline . $this->finalBody;
+				}
+
+				if ($this->sendMultipart !== false)
+				{
+					$this->finalBody .= '--' . $boundary . '--';
+				}
+
+				return;
+
+			case 'plain-attach':
+
+				$boundary = uniqid('B_ATC_', true);
+				$hdr     .= 'Content-Type: multipart/mixed; boundary="' . $boundary . '"';
+
+				if ($this->getProtocol() === 'mail')
+				{
+					$this->headerStr .= $hdr;
+				}
+
+				$body .= $this->getMimeMessage() . $this->newline
+						. $this->newline
+						. '--' . $boundary . $this->newline
+						. 'Content-Type: text/plain; charset=' . $this->charset . $this->newline
+						. 'Content-Transfer-Encoding: ' . $this->getEncoding() . $this->newline
+						. $this->newline
+						. $this->body . $this->newline . $this->newline;
+
+				$this->appendAttachments($body, $boundary);
+
+				break;
+			case 'html-attach':
+
+				$alt_boundary  = uniqid('B_ALT_', true);
+				$last_boundary = null;
+
+				if ($this->attachmentsHaveMultipart('mixed'))
+				{
+					$atc_boundary  = uniqid('B_ATC_', true);
+					$hdr          .= 'Content-Type: multipart/mixed; boundary="' . $atc_boundary . '"';
+					$last_boundary = $atc_boundary;
+				}
+
+				if ($this->attachmentsHaveMultipart('related'))
+				{
+					$rel_boundary        = uniqid('B_REL_', true);
+					$rel_boundary_header = 'Content-Type: multipart/related; boundary="' . $rel_boundary . '"';
+
+					if (isset($last_boundary))
+					{
+						$body .= '--' . $last_boundary . $this->newline . $rel_boundary_header;
+					}
+					else
+					{
+						$hdr .= $rel_boundary_header;
+					}
+
+					$last_boundary = $rel_boundary;
+				}
+
+				if ($this->getProtocol() === 'mail')
+				{
+					$this->headerStr .= $hdr;
+				}
+
+				static::strlen($body) && $body .= $this->newline . $this->newline;
+				$body                          .= $this->getMimeMessage() . $this->newline . $this->newline
+						. '--' . $last_boundary . $this->newline
+						. 'Content-Type: multipart/alternative; boundary="' . $alt_boundary . '"' . $this->newline . $this->newline
+						. '--' . $alt_boundary . $this->newline
+						. 'Content-Type: text/plain; charset=' . $this->charset . $this->newline
+						. 'Content-Transfer-Encoding: ' . $this->getEncoding() . $this->newline . $this->newline
+						. $this->getAltMessage() . $this->newline . $this->newline
+						. '--' . $alt_boundary . $this->newline
+						. 'Content-Type: text/html; charset=' . $this->charset . $this->newline
+						. 'Content-Transfer-Encoding: quoted-printable' . $this->newline . $this->newline
+						. $this->prepQuotedPrintable($this->body) . $this->newline . $this->newline
+						. '--' . $alt_boundary . '--' . $this->newline . $this->newline;
+
+				if (! empty($rel_boundary))
+				{
+					$body .= $this->newline . $this->newline;
+					$this->appendAttachments($body, $rel_boundary, 'related');
+				}
+
+				// multipart/mixed attachments
+				if (! empty($atc_boundary))
+				{
+					$body .= $this->newline . $this->newline;
+					$this->appendAttachments($body, $atc_boundary, 'mixed');
+				}
+
+				break;
+		}
+
+		$this->finalBody = ($this->getProtocol() === 'mail') ? $body : $hdr . $this->newline . $this->newline . $body;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Prepares attachment string
+	 *
+	 * @param string      &$body     Message body to append to
+	 * @param string      $boundary  Multipart boundary
+	 * @param string|null $multipart When provided, only attachments of this type will be processed
+	 *
+	 * @return string
+	 */
+	protected function appendAttachments(&$body, $boundary, $multipart = null)
+	{
+		for ($i = 0, $c = count($this->attachments); $i < $c; $i ++)
+		{
+			if (isset($multipart) && $this->attachments[$i]['multipart'] !== $multipart)
+			{
+				continue;
+			}
+
+			$name = isset($this->attachments[$i]['name'][1]) ? $this->attachments[$i]['name'][1] : basename($this->attachments[$i]['name'][0]);
+
+			$body .= '--' . $boundary . $this->newline
+					. 'Content-Type: ' . $this->attachments[$i]['type'] . '; name="' . $name . '"' . $this->newline
+					. 'Content-Disposition: ' . $this->attachments[$i]['disposition'] . ';' . $this->newline
+					. 'Content-Transfer-Encoding: base64' . $this->newline
+					. (empty($this->attachments[$i]['cid']) ? '' : 'Content-ID: <' . $this->attachments[$i]['cid'] . '>' . $this->newline)
+					. $this->newline
+					. $this->attachments[$i]['content'] . $this->newline;
+		}
+
+		// $name won't be set if no attachments were appended,
+		// and therefore a boundary wouldn't be necessary
+		empty($name) || $body .= '--' . $boundary . '--';
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Prep Quoted Printable
+	 *
+	 * Prepares string for Quoted-Printable Content-Transfer-Encoding
+	 * Refer to RFC 2045 http://www.ietf.org/rfc/rfc2045.txt
+	 *
+	 * @param string $str
+	 *
+	 * @return string
+	 */
+	protected function prepQuotedPrintable($str)
+	{
+		// ASCII code numbers for "safe" characters that can always be
+		// used literally, without encoding, as described in RFC 2049.
+		// http://www.ietf.org/rfc/rfc2049.txt
+		static $ascii_safe_chars = [
+			// ' (  )   +   ,   -   .   /   :   =   ?
+			39,
+			40,
+			41,
+			43,
+			44,
+			45,
+			46,
+			47,
+			58,
+			61,
+			63,
+			// numbers
+			48,
+			49,
+			50,
+			51,
+			52,
+			53,
+			54,
+			55,
+			56,
+			57,
+			// upper-case letters
+			65,
+			66,
+			67,
+			68,
+			69,
+			70,
+			71,
+			72,
+			73,
+			74,
+			75,
+			76,
+			77,
+			78,
+			79,
+			80,
+			81,
+			82,
+			83,
+			84,
+			85,
+			86,
+			87,
+			88,
+			89,
+			90,
+			// lower-case letters
+			97,
+			98,
+			99,
+			100,
+			101,
+			102,
+			103,
+			104,
+			105,
+			106,
+			107,
+			108,
+			109,
+			110,
+			111,
+			112,
+			113,
+			114,
+			115,
+			116,
+			117,
+			118,
+			119,
+			120,
+			121,
+			122,
+		];
+
+		// We are intentionally wrapping so mail servers will encode characters
+		// properly and MUAs will behave, so {unwrap} must go!
+		$str = str_replace(['{unwrap}', '{/unwrap}'], '', $str);
+
+		// RFC 2045 specifies CRLF as "\r\n".
+		// However, many developers choose to override that and violate
+		// the RFC rules due to (apparently) a bug in MS Exchange,
+		// which only works with "\n".
+		if ($this->CRLF === "\r\n")
+		{
+			return quoted_printable_encode($str);
+		}
+
+		// Reduce multiple spaces & remove nulls
+		$str = preg_replace(['| +|', '/\x00+/'], [' ', ''], $str);
+
+		// Standardize newlines
+		if (strpos($str, "\r") !== false)
+		{
+			$str = str_replace(["\r\n", "\r"], "\n", $str);
+		}
+
+		$escape = '=';
+		$output = '';
+
+		foreach (explode("\n", $str) as $line)
+		{
+			$length = static::strlen($line);
+			$temp   = '';
+
+			// Loop through each character in the line to add soft-wrap
+			// characters at the end of a line " =\r\n" and add the newly
+			// processed line(s) to the output (see comment on $crlf class property)
+			for ($i = 0; $i < $length; $i ++)
+			{
+				// Grab the next character
+				$char  = $line[$i];
+				$ascii = ord($char);
+
+				// Convert spaces and tabs but only if it's the end of the line
+				if ($ascii === 32 || $ascii === 9)
+				{
+					if ($i === ($length - 1))
+					{
+						$char = $escape . sprintf('%02s', dechex($ascii));
+					}
+				}
+				// DO NOT move this below the $ascii_safe_chars line!
+				//
+				// = (equals) signs are allowed by RFC2049, but must be encoded
+				// as they are the encoding delimiter!
+				elseif ($ascii === 61)
+				{
+					$char = $escape . strtoupper(sprintf('%02s', dechex($ascii)));  // =3D
+				}
+				elseif (! in_array($ascii, $ascii_safe_chars, true))
+				{
+					$char = $escape . strtoupper(sprintf('%02s', dechex($ascii)));
+				}
+
+				// If we're at the character limit, add the line to the output,
+				// reset our temp variable, and keep on chuggin'
+				if ((static::strlen($temp) + static::strlen($char)) >= 76)
+				{
+					$output .= $temp . $escape . $this->CRLF;
+					$temp    = '';
+				}
+
+				// Add the character to our temporary line
+				$temp .= $char;
+			}
+
+			// Add our completed line to the output
+			$output .= $temp . $this->CRLF;
+		}
+
+		// get rid of extra CRLF tacked onto the end
+		return static::substr($output, 0, static::strlen($this->CRLF) * -1);
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Prep Q Encoding
+	 *
+	 * Performs "Q Encoding" on a string for use in email headers.
+	 * It's related but not identical to quoted-printable, so it has its
+	 * own method.
+	 *
+	 * @param string $str
+	 *
+	 * @return string
+	 */
+	protected function prepQEncoding($str)
+	{
+		$str = str_replace(["\r", "\n"], '', $str);
+
+		if ($this->charset === 'UTF-8')
+		{
+			// Note: We used to have mb_encode_mimeheader() as the first choice
+			//       here, but it turned out to be buggy and unreliable. DO NOT
+			//       re-add it! -- Narf
+			if (extension_loaded('iconv'))
+			{
+				$output = @iconv_mime_encode(
+								'', $str, [
+									'scheme'           => 'Q',
+									'line-length'      => 76,
+									'input-charset'    => $this->charset,
+									'output-charset'   => $this->charset,
+									'line-break-chars' => $this->CRLF,
+								]);
+
+				// There are reports that iconv_mime_encode() might fail and return FALSE
+				if ($output !== false)
+				{
+					// iconv_mime_encode() will always put a header field name.
+					// We've passed it an empty one, but it still prepends our
+					// encoded string with ': ', so we need to strip it.
+					return static::substr($output, 2);
+				}
+
+				$chars = iconv_strlen($str, 'UTF-8');
+			}
+			elseif (extension_loaded('mbstring'))
+			{
+				$chars = mb_strlen($str, 'UTF-8');
+			}
+		}
+
+		// We might already have this set for UTF-8
+		isset($chars) || $chars = static::strlen($str);
+
+		$output = '=?' . $this->charset . '?Q?';
+		for ($i = 0, $length = static::strlen($output); $i < $chars; $i ++)
+		{
+			$chr = ($this->charset === 'UTF-8' && ICONV_ENABLED === true) ? '=' . implode('=', str_split(strtoupper(bin2hex(iconv_substr($str, $i, 1, $this->charset))), 2)) : '=' . strtoupper(bin2hex($str[$i]));
+
+			// RFC 2045 sets a limit of 76 characters per line.
+			// We'll append ?= to the end of each line though.
+			if ($length + ($l = static::strlen($chr)) > 74)
+			{
+				$output .= '?=' . $this->CRLF // EOL
+						. ' =?' . $this->charset . '?Q?' . $chr; // New line
+				$length  = 6 + static::strlen($this->charset) + $l; // Reset the length for the new line
+			}
+			else
+			{
+				$output .= $chr;
+				$length += $l;
+			}
+		}
+
+		// End the header
+		return $output . '?=';
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Send a Message
+	 *
+	 * @param boolean $autoClear
+	 *
+	 * @return boolean
+	 */
+	public function send(Message $message, bool $autoClear = true, bool $reallySend = true)
+	{
+		if (! isset($this->headers['From']) && ! empty($this->fromEmail))
+		{
+			$this->setFrom($this->fromEmail, $this->fromName);
+		}
+
+		if (! isset($this->headers['From']))
+		{
+				throw MailerException::forNoFrom();
+		}
+
+		if ($this->replyToFlag === false)
+		{
+			$this->setReplyTo($this->headers['From']);
+		}
+
+		if (empty($this->recipients) && ! isset($this->headers['To']) && empty($this->BCCArray) && ! isset($this->headers['Bcc']) && ! isset($this->headers['Cc'])
+		)
+		{
+				throw MailerException::forNoRecipients();
+		}
+
+		$this->buildHeaders();
+
+		if ($this->BCCBatchMode && count($this->BCCArray) > $this->BCCBatchSize)
+		{
+			$this->batchBCCSend();
+
+			if ($autoClear)
+			{
+				$this->clear();
+			}
+
+			return true;
+		}
+
+		$this->buildMessage();
+		$result = $this->spoolEmail();
+
+		if ($result && $autoClear)
+		{
+			$this->clear();
+		}
+
+		return $result;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Batch Bcc Send. Sends groups of BCCs in batches
+	 */
+	public function batchBCCSend()
+	{
+		$float = $this->BCCBatchSize - 1;
+		$set   = '';
+		$chunk = [];
+
+		for ($i = 0, $c = count($this->BCCArray); $i < $c; $i ++)
+		{
+			if (isset($this->BCCArray[$i]))
+			{
+				$set .= ', ' . $this->BCCArray[$i];
+			}
+
+			if ($i === $float)
+			{
+				$chunk[] = static::substr($set, 1);
+				$float  += $this->BCCBatchSize;
+				$set     = '';
+			}
+
+			if ($i === $c - 1)
+			{
+				$chunk[] = static::substr($set, 1);
+			}
+		}
+
+		for ($i = 0, $c = count($chunk); $i < $c; $i ++)
+		{
+			unset($this->headers['Bcc']);
+
+			$bcc = $this->cleanEmail($this->stringToArray($chunk[$i]));
+
+			if ($this->protocol !== 'smtp')
+			{
+				$this->setHeader('Bcc', implode(', ', $bcc));
+			}
+			else
+			{
+				$this->BCCArray = $bcc;
+			}
+
+			$this->buildMessage();
+			$this->spoolEmail();
+		}
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Unwrap special elements
+	 */
+	protected function unwrapSpecials()
+	{
+		$this->finalBody = preg_replace_callback(
+				'/\{unwrap\}(.*?)\{\/unwrap\}/si', [
+					$this,
+					'removeNLCallback',
+				], $this->finalBody
+		);
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Strip line-breaks via callback
+	 *
+	 * @param string $matches
+	 *
+	 * @return string
+	 */
+	protected function removeNLCallback($matches)
+	{
+		if (strpos($matches[1], "\r") !== false || strpos($matches[1], "\n") !== false)
+		{
+			$matches[1] = str_replace(["\r\n", "\r", "\n"], '', $matches[1]);
+		}
+
+		return $matches[1];
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Spool mail to the mail server
+	 *
+	 * @return boolean
+	 */
+	protected function spoolEmail()
+	{
+		$this->unwrapSpecials();
+
+		$protocol = $this->getProtocol();
+		$method   = 'sendWith' . ucfirst($protocol);
+		try
+		{
+			$success = $this->$method();
+		}
+		catch (\ErrorException $e)
+		{
+			$success = false;
+			$this->logger->error('Mailer: ' . $method . ' throwed ' . $e->getMessage());
+		}
+
+		if (! $success)
+		{
+				throw MailerException::forSendFailure($protocol === 'mail' ? 'PHPMail' : ucfirst($protocol));
+		}
+
+		$this->setErrorMessage(lang('Mailer.sent', [$protocol]));
+
+		return true;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Validate email for shell
+	 *
+	 * Applies stricter, shell-safe validation to email addresses.
+	 * Introduced to prevent RCE via sendmail's -f option.
+	 *
+	 * @see     https://github.com/codeigniter4/CodeIgniter/issues/4963
+	 * @see     https://gist.github.com/Zenexer/40d02da5e07f151adeaeeaa11af9ab36
+	 * @license https://creativecommons.org/publicdomain/zero/1.0/    CC0 1.0, Public Domain
+	 *
+	 * Credits for the base concept go to Paul Buonopane <paul@namepros.com>
+	 *
+	 * @param string &$email
+	 *
+	 * @return boolean
+	 */
+	protected function validateEmailForShell(&$email)
+	{
+		if (function_exists('idn_to_ascii') && $atpos = strpos($email, '@'))
+		{
+			$email = static::substr($email, 0, ++ $atpos) . idn_to_ascii(
+							static::substr($email, $atpos), 0, INTL_IDNA_VARIANT_UTS46
+			);
+		}
+
+		return (filter_var($email, FILTER_VALIDATE_EMAIL) === $email && preg_match('#\A[a-z0-9._+-]+@[a-z0-9.-]{1,253}\z#i', $email));
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Send using mail()
+	 *
+	 * @return boolean
+	 */
+	protected function sendWithMail()
+	{
+		if (is_array($this->recipients))
+		{
+			$this->recipients = implode(', ', $this->recipients);
+		}
+
+		// _validate_email_for_shell() below accepts by reference,
+		// so this needs to be assigned to a variable
+		$from = $this->cleanEmail($this->headers['Return-Path']);
+
+		if (! $this->validateEmailForShell($from))
+		{
+			return mail($this->recipients, $this->subject, $this->finalBody, $this->headerStr);
+		}
+
+		// most documentation of sendmail using the "-f" flag lacks a space after it, however
+		// we've encountered servers that seem to require it to be in place.
+		return mail($this->recipients, $this->subject, $this->finalBody, $this->headerStr, '-f ' . $from);
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Send using Sendmail
+	 *
+	 * @return boolean
+	 */
+	protected function sendWithSendmail()
+	{
+		// _validate_email_for_shell() below accepts by reference,
+		// so this needs to be assigned to a variable
+		$from = $this->cleanEmail($this->headers['From']);
+		if ($this->validateEmailForShell($from))
+		{
+			$from = '-f ' . $from;
+		}
+		else
+		{
+			$from = '';
+		}
+
+		// is popen() enabled?
+		if (! function_usable('popen') || false === ($fp = @popen($this->mailPath . ' -oi ' . $from . ' -t', 'w')))
+		{
+			// server probably has popen disabled, so nothing we can do to get a verbose error.
+			return false;
+		}
+
+		fputs($fp, $this->headerStr);
+		fputs($fp, $this->finalBody);
+
+		$status = pclose($fp);
+
+		if ($status !== 0)
+		{
+				throw MailerException::forNosocket($status);
+		}
+
+		return true;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Send using SMTP
+	 *
+	 * @return boolean
+	 */
+	protected function sendWithSmtp()
+	{
+		if ($this->SMTPHost === '')
+		{
+				throw MailerException::forNoHostname();
+		}
+
+		if (! $this->SMTPConnect() || ! $this->SMTPAuthenticate())
+		{
+			return false;
+		}
+
+		if (! $this->sendCommand('from', $this->cleanEmail($this->headers['From'])))
+		{
+			$this->SMTPEnd();
+
+			return false;
+		}
+
+		foreach ($this->recipients as $val)
+		{
+			if (! $this->sendCommand('to', $val))
+			{
+				$this->SMTPEnd();
+
+				return false;
+			}
+		}
+
+		foreach ($this->CCArray as $val)
+		{
+			if ($val !== '' && ! $this->sendCommand('to', $val))
+			{
+				$this->SMTPEnd();
+
+				return false;
+			}
+		}
+
+		foreach ($this->BCCArray as $val)
+		{
+			if ($val !== '' && ! $this->sendCommand('to', $val))
+			{
+				$this->SMTPEnd();
+
+				return false;
+			}
+		}
+
+		if (! $this->sendCommand('data'))
+		{
+			$this->SMTPEnd();
+
+			return false;
+		}
+
+		// perform dot transformation on any lines that begin with a dot
+		$this->sendData($this->headerStr . preg_replace('/^\./m', '..$1', $this->finalBody));
+
+		$this->sendData('.');
+		$reply = $this->getSMTPData();
+		$this->setErrorMessage($reply);
+
+		$this->SMTPEnd();
+
+		if (strpos($reply, '250') !== 0)
+		{
+				throw MailerException::forSMTPError($reply);
+		}
+
+		return true;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * SMTP End
+	 *
+	 * Shortcut to send RSET or QUIT depending on keep-alive
+	 */
+	protected function SMTPEnd()
+	{
+		$this->sendCommand($this->SMTPKeepAlive ? 'reset' : 'quit');
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * SMTP Connect
+	 *
+	 * @return string
+	 */
+	protected function SMTPConnect()
+	{
+		if (is_resource($this->SMTPConnect))
+		{
+			return true;
+		}
+
+		$ssl = ($this->SMTPCrypto === 'ssl') ? 'ssl://' : '';
+
+		$this->SMTPConnect = fsockopen(
+				$ssl . $this->SMTPHost, $this->SMTPPort, $errno, $errstr, $this->SMTPTimeout
+		);
+
+		if (! is_resource($this->SMTPConnect))
+		{
+				throw MailerException::forSMTPError($errno . ' ' . $errstr);
+		}
+
+		stream_set_timeout($this->SMTPConnect, $this->SMTPTimeout);
+		$this->setErrorMessage($this->getSMTPData());
+
+		if ($this->SMTPCrypto === 'tls')
+		{
+			$this->sendCommand('hello');
+			$this->sendCommand('starttls');
+
+			$crypto = stream_socket_enable_crypto($this->SMTPConnect, true, STREAM_CRYPTO_METHOD_TLS_CLIENT);
+
+			if ($crypto !== true)
+			{
+				throw MailerException::forSMTPError($this->getSMTPData());
+			}
+		}
+
+		return $this->sendCommand('hello');
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Send SMTP command
+	 *
+	 * @param string $cmd
+	 * @param string $data
+	 *
+	 * @return boolean
+	 */
+	protected function sendCommand($cmd, $data = '')
+	{
+		switch ($cmd)
+		{
+			case 'hello':
+				if ($this->SMTPAuth || $this->getEncoding() === '8bit')
+				{
+					$this->sendData('EHLO ' . $this->getHostname());
+				}
+				else
+				{
+					$this->sendData('HELO ' . $this->getHostname());
+				}
+
+				$resp = 250;
+				break;
+			case 'starttls':
+				$this->sendData('STARTTLS');
+				$resp = 220;
+				break;
+			case 'from':
+				$this->sendData('MAIL FROM:<' . $data . '>');
+				$resp = 250;
+				break;
+			case 'to':
+				if ($this->DSN)
+				{
+					$this->sendData('RCPT TO:<' . $data . '> NOTIFY=SUCCESS,DELAY,FAILURE ORCPT=rfc822;' . $data);
+				}
+				else
+				{
+					$this->sendData('RCPT TO:<' . $data . '>');
+				}
+				$resp = 250;
+				break;
+			case 'data':
+				$this->sendData('DATA');
+				$resp = 354;
+				break;
+			case 'reset':
+				$this->sendData('RSET');
+				$resp = 250;
+				break;
+			case 'quit':
+				$this->sendData('QUIT');
+				$resp = 221;
+				break;
+		}
+
+		$reply = $this->getSMTPData();
+
+		$this->debugMessage[] = '<pre>' . $cmd . ': ' . $reply . '</pre>';
+
+		if ((int) static::substr($reply, 0, 3) !== $resp)
+		{
+				throw MailerException::forSMTPError($reply);
+		}
+
+		if ($cmd === 'quit')
+		{
+			fclose($this->SMTPConnect);
+		}
+
+		return true;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * SMTP Authenticate
+	 *
+	 * @return boolean
+	 */
+	protected function SMTPAuthenticate()
+	{
+		if (! $this->SMTPAuth)
+		{
+			return true;
+		}
+
+		if ($this->SMTPUser === '' && $this->SMTPPass === '')
+		{
+				throw MailerException::forNoSMTPAuth();
+		}
+
+		$this->sendData('AUTH LOGIN');
+		$reply = $this->getSMTPData();
+
+		if (strpos($reply, '503') === 0)    // Already authenticated
+		{
+			return true;
+		}
+		elseif (strpos($reply, '334') !== 0)
+		{
+				throw MailerException::forFailedSMTPLogin($reply);
+		}
+
+		$this->sendData(base64_encode($this->SMTPUser));
+		$reply = $this->getSMTPData();
+
+		if (strpos($reply, '334') !== 0)
+		{
+				throw MailerException::forSMTPAuthUsername($reply);
+		}
+
+		$this->sendData(base64_encode($this->SMTPPass));
+		$reply = $this->getSMTPData();
+
+		if (strpos($reply, '235') !== 0)
+		{
+				throw MailerException::forSMTPAuthPassword($reply);
+		}
+
+		if ($this->SMTPKeepAlive)
+		{
+			$this->SMTPAuth = false;
+		}
+
+		return true;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Send SMTP data
+	 *
+	 * @param string $data
+	 *
+	 * @return boolean
+	 */
+	protected function sendData($data)
+	{
+		$data .= $this->newline;
+		for ($written = $timestamp = 0, $length = static::strlen($data); $written < $length; $written += $result)
+		{
+			if (($result = fwrite($this->SMTPConnect, static::substr($data, $written))) === false)
+			{
+				break;
+			}
+			// See https://bugs.php.net/bug.php?id=39598 and http://php.net/manual/en/function.fwrite.php#96951
+			elseif ($result === 0)
+			{
+				if ($timestamp === 0)
+				{
+					$timestamp = time();
+				}
+				elseif ($timestamp < (time() - $this->SMTPTimeout))
+				{
+					$result = false;
+					break;
+				}
+
+				usleep(250000);
+				continue;
+			}
+			else
+			{
+				$timestamp = 0;
+			}
+		}
+
+		if ($result === false)
+		{
+				throw MailerException::forSMTPDataFailure($data);
+		}
+
+		return true;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Get SMTP data
+	 *
+	 * @return string
+	 */
+	protected function getSMTPData()
+	{
+		$data = '';
+
+		while ($str = fgets($this->SMTPConnect, 512))
+		{
+			$data .= $str;
+
+			if ($str[3] === ' ')
+			{
+				break;
+			}
+		}
+
+		return $data;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Get Hostname
+	 *
+	 * There are only two legal types of hostname - either a fully
+	 * qualified domain name (eg: "mail.example.com") or an IP literal
+	 * (eg: "[1.2.3.4]").
+	 *
+	 * @link https://tools.ietf.org/html/rfc5321#section-2.3.5
+	 * @link http://cbl.abuseat.org/namingproblems.html
+	 *
+	 * @return string
+	 */
+	protected function getHostname()
+	{
+		if (isset($_SERVER['SERVER_NAME']))
+		{
+			return $_SERVER['SERVER_NAME'];
+		}
+
+		return isset($_SERVER['SERVER_ADDR']) ? '[' . $_SERVER['SERVER_ADDR'] . ']' : '[127.0.0.1]';
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Get Debug Message
+	 *
+	 * @param array $include List of raw data chunks to include in the output
+	 *                       Valid options are: 'headers', 'subject', 'body'
+	 *
+	 * @return string
+	 */
+	public function printDebugger($include = ['headers', 'subject', 'body'])
+	{
+		$msg = implode('', $this->debugMessage);
+
+		// Determine which parts of our raw data needs to be printed
+		$raw_data                      = '';
+		is_array($include) || $include = [$include];
+
+		in_array('headers', $include, true) && $raw_data  = htmlspecialchars($this->headerStr) . "\n";
+		in_array('subject', $include, true) && $raw_data .= htmlspecialchars($this->subject) . "\n";
+		in_array('body', $include, true) && $raw_data    .= htmlspecialchars($this->finalBody);
+
+		return $msg . ($raw_data === '' ? '' : '<pre>' . $raw_data . '</pre>');
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Set Message
+	 *
+	 * @param string $msg
+	 */
+	protected function setErrorMessage($msg)
+	{
+		$this->debugMessage[] = $msg . '<br />';
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Mime Types
+	 *
+	 * @param string $ext
+	 *
+	 * @return string
+	 */
+	protected function mimeTypes($ext = '')
+	{
+		$mime = Mimes::guessTypeFromExtension(strtolower($ext));
+
+		return ! empty($mime) ? $mime : 'application/x-unknown-content-type';
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Destructor
+	 */
+	public function __destruct()
+	{
+		is_resource($this->SMTPConnect) && $this->sendCommand('quit');
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Byte-safe strlen()
+	 *
+	 * @param string $str
+	 *
+	 * @return integer
+	 */
+	protected static function strlen($str)
+	{
+		return (static::$func_overload) ? mb_strlen($str, '8bit') : strlen($str);
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Byte-safe substr()
+	 *
+	 * @param string       $str
+	 * @param integer      $start
+	 * @param integer|null $length
+	 *
+	 * @return string
+	 */
+	protected static function substr($str, $start, $length = null)
+	{
+		if (static::$func_overload)
+		{
+			return mb_substr($str, $start, $length, '8bit');
+		}
+
+		return isset($length) ? substr($str, $start, $length) : substr($str, $start);
+	}
+
+}
diff --git a/system/Mailer/Handlers/SMTPHandler.php b/system/Mailer/Handlers/SMTPHandler.php
new file mode 100644
index 000000000000..9e7248fbd2f1
--- /dev/null
+++ b/system/Mailer/Handlers/SMTPHandler.php
@@ -0,0 +1,1638 @@
+<?php
+namespace CodeIgniter\Mailer\Handlers;
+
+/**
+ * CodeIgniter
+ *
+ * An open source application development framework for PHP
+ *
+ * This content is released under the MIT License (MIT)
+ *
+ * Copyright (c) 2014 - 2018, British Columbia Institute of Technology
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ * @package    CodeIgniter
+ * @author     EllisLab Dev Team
+ * @copyright  Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
+ * @copyright  Copyright (c) 2014 - 2018, British Columbia Institute of Technology (http://bcit.ca/)
+ * @license    http://opensource.org/licenses/MIT    MIT License
+ * @link       https://codeigniter.com
+ * @since      Version 1.0.0
+ * @filesource
+ */
+
+use CodeIgniter\Mailer\Message;
+use CodeIgniter\Mailer\Exceptions\MailerException;
+use Config\Mimes;
+use Psr\Log\LoggerAwareTrait;
+
+/**
+ * SMTP Mailer
+ *
+ * Permits a Message to be sent using SMTP.
+ *
+ * @package    CodeIgniter
+ * @subpackage Libraries
+ * @category   Libraries
+ * @author     EllisLab Dev Team
+ * @link       https://codeigniter.com/user_guide/libraries/email.html
+ */
+class SMTPHandler extends BaseHandler
+{
+
+	/**
+	 * Message format.
+	 *
+	 * @var string 'text' or 'html'
+	 */
+	public $mailType = 'text';
+
+	/**
+	 * Character set (default: utf-8)
+	 *
+	 * @var string
+	 */
+	public $charset = 'utf-8';
+
+	/**
+	 * Alternative message (for HTML messages only)
+	 *
+	 * @var string
+	 */
+	public $altMessage = '';
+
+	/**
+	 * Whether to validate email addresses.
+	 *
+	 * @var boolean
+	 */
+	public $validate = true;
+
+	/**
+	 * X-Priority header value.
+	 *
+	 * @var integer 1-5
+	 */
+	public $priority = 3;            // Default priority (1 - 5)
+
+	/**
+	 * Newline character sequence.
+	 * Use "\r\n" to comply with RFC 822.
+	 *
+	 * @link http://www.ietf.org/rfc/rfc822.txt
+	 * @var  string "\r\n" or "\n"
+	 */
+	public $newline = "\n";            // Default newline. "\r\n" or "\n" (Use "\r\n" to comply with RFC 822)
+
+	/**
+	 * CRLF character sequence
+	 *
+	 * RFC 2045 specifies that for 'quoted-printable' encoding,
+	 * "\r\n" must be used. However, it appears that some servers
+	 * (even on the receiving end) don't handle it properly and
+	 * switching to "\n", while improper, is the only solution
+	 * that seems to work for all environments.
+	 *
+	 * @link http://www.ietf.org/rfc/rfc822.txt
+	 * @var  string
+	 */
+	public $CRLF = "\n";
+
+	/**
+	 * Whether to use Delivery Status Notification.
+	 *
+	 * @var boolean
+	 */
+	public $DSN = false;
+
+	/**
+	 * Whether to send multipart alternatives.
+	 * Yahoo! doesn't seem to like these.
+	 *
+	 * @var boolean
+	 */
+	public $sendMultipart = true;
+
+	/**
+	 * Whether to send messages to BCC recipients in batches.
+	 *
+	 * @var boolean
+	 */
+	public $BCCBatchMode = false;
+
+	/**
+	 * BCC Batch max number size.
+	 *
+	 * @see Mailer::$BCCBatchMode
+	 * @var integer
+	 */
+	public $BCCBatchSize = 200;
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Subject header
+	 *
+	 * @var string
+	 */
+	protected $subject = '';
+
+	/**
+	 * Message body
+	 *
+	 * @var string
+	 */
+	protected $body = '';
+
+	/**
+	 * Final message body to be sent.
+	 *
+	 * @var string
+	 */
+	protected $finalBody = '';
+
+	/**
+	 * Final headers to send
+	 *
+	 * @var string
+	 */
+	protected $headerStr = '';
+
+	/**
+	 * SMTP Connection socket placeholder
+	 *
+	 * @var resource
+	 */
+	protected $SMTPConnect = '';
+
+	/**
+	 * Mail encoding
+	 *
+	 * @var string '8bit' or '7bit'
+	 */
+	protected $encoding = '8bit';
+
+	/**
+	 * Whether to send a Reply-To header
+	 *
+	 * @var boolean
+	 */
+	protected $replyToFlag = false;
+
+	/**
+	 * Debug messages
+	 *
+	 * @see Mailer::printDebugger()
+	 * @var array
+	 */
+	protected $debugMessage = [];
+
+	/**
+	 * Recipients
+	 *
+	 * @var array
+	 */
+	protected $recipients = [];
+
+	/**
+	 * CC Recipients
+	 *
+	 * @var array
+	 */
+	protected $CCArray = [];
+
+	/**
+	 * BCC Recipients
+	 *
+	 * @var array
+	 */
+	protected $BCCArray = [];
+
+	/**
+	 * Message headers
+	 *
+	 * @var array
+	 */
+	protected $headers = [];
+
+	/**
+	 * Attachment data
+	 *
+	 * @var array
+	 */
+	protected $attachments = [];
+
+	/**
+	 * Valid $protocol values
+	 *
+	 * @see Mailer::$protocol
+	 * @var array
+	 */
+	protected $protocols = [
+		'mail',
+		'sendmail',
+		'smtp',
+	];
+
+	/**
+	 * Base charsets
+	 *
+	 * Character sets valid for 7-bit encoding,
+	 * excluding language suffix.
+	 *
+	 * @var array
+	 */
+	protected $baseCharsets = [
+		'us-ascii',
+		'iso-2022-',
+	];
+
+	/**
+	 * Bit depths
+	 *
+	 * Valid mail encodings
+	 *
+	 * @see Mailer::$encoding
+	 * @var array
+	 */
+	protected $bitDepths = [
+		'7bit',
+		'8bit',
+	];
+
+	/**
+	 * $priority translations
+	 *
+	 * Actual values to send with the X-Priority header
+	 *
+	 * @var array
+	 */
+	protected $priorities = [
+		1 => '1 (Highest)',
+		2 => '2 (High)',
+		3 => '3 (Normal)',
+		4 => '4 (Low)',
+		5 => '5 (Lowest)',
+	];
+
+	/**
+	 * mbstring.func_overload flag
+	 *
+	 * @var boolean
+	 */
+	protected static $func_overload;
+
+	/**
+	 * Logger instance to record error messages and awarnings.
+	 *
+	 * @var \PSR\Log\LoggerInterface
+	 */
+	protected $logger;
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Constructor - Sets Mailer Preferences
+	 *
+	 * The constructor can be passed an array of config values
+	 *
+	 * @param array|null $config
+	 */
+	public function __construct($config = null)
+	{
+		$this->protocol = 'smtp';
+		$this->initialize($config);
+
+		log_message('info', 'Mailer Class Initialized');
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Initialize preferences
+	 *
+	 * @param array|\Config\Mailer $config
+	 *
+	 * @return Mailer
+	 */
+	public function initialize($config)
+	{
+		$this->clear();
+
+		if ($config instanceof \Config\Mailer)
+		{
+			$config = get_object_vars($config);
+		}
+
+		foreach (get_class_vars(get_class($this)) as $key => $value)
+		{
+			if (property_exists($this, $key) && isset($config[$key]))
+			{
+				$method = 'set' . ucfirst($key);
+
+				if (method_exists($this, $method))
+				{
+					$this->$method($config[$key]);
+				}
+				else
+				{
+					$this->$key = $config[$key];
+				}
+			}
+		}
+
+		$this->charset  = strtoupper($this->charset);
+		$this->SMTPAuth = isset($this->SMTPUser[0], $this->SMTPPass[0]);
+
+		return $this;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Initialize the Mailer Data
+	 *
+	 * @param boolean $clearAttachments
+	 *
+	 * @return Mailer
+	 */
+	public function clear($clearAttachments = false)
+	{
+		$this->subject      = '';
+		$this->body         = '';
+		$this->finalBody    = '';
+		$this->headerStr    = '';
+		$this->replyToFlag  = false;
+		$this->recipients   = [];
+		$this->CCArray      = [];
+		$this->BCCArray     = [];
+		$this->headers      = [];
+		$this->debugMessage = [];
+
+		//      $this->setHeader('Date', $this->setDate());
+
+		if ($clearAttachments !== false)
+		{
+			$this->attachments = [];
+		}
+
+		return $this;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Build final headers
+	 */
+	protected function buildHeaders()
+	{
+		$this->setHeader('User-Agent', $this->userAgent);
+		$this->setHeader('X-Sender', $this->cleanEmail($this->headers['From']));
+		$this->setHeader('X-Mailer', $this->userAgent);
+		$this->setHeader('X-Priority', $this->priorities[$this->priority]);
+		$this->setHeader('Message-ID', $this->getMessageID());
+		$this->setHeader('Mime-Version', '1.0');
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Write Headers as a string
+	 */
+	protected function writeHeaders()
+	{
+		if ($this->protocol === 'mail')
+		{
+			if (isset($this->headers['Subject']))
+			{
+				$this->subject = $this->headers['Subject'];
+				unset($this->headers['Subject']);
+			}
+		}
+
+		reset($this->headers);
+		$this->headerStr = '';
+
+		foreach ($this->headers as $key => $val)
+		{
+			$val = trim($val);
+
+			if ($val !== '')
+			{
+				$this->headerStr .= $key . ': ' . $val . $this->newline;
+			}
+		}
+
+		if ($this->getProtocol() === 'mail')
+		{
+			$this->headerStr = rtrim($this->headerStr);
+		}
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Build Final Body and attachments
+	 */
+	protected function buildMessage()
+	{
+		if ($this->wordWrap === true && $this->mailType !== 'html')
+		{
+			$this->body = $this->wordWrap($this->body);
+		}
+
+		$this->writeHeaders();
+
+		$hdr  = ($this->getProtocol() === 'mail') ? $this->newline : '';
+		$body = '';
+
+		switch ($this->getContentType())
+		{
+			case 'plain':
+
+				$hdr .= 'Content-Type: text/plain; charset=' . $this->charset . $this->newline
+						. 'Content-Transfer-Encoding: ' . $this->getEncoding();
+
+				if ($this->getProtocol() === 'mail')
+				{
+					$this->headerStr .= $hdr;
+					$this->finalBody  = $this->body;
+				}
+				else
+				{
+					$this->finalBody = $hdr . $this->newline . $this->newline . $this->body;
+				}
+
+				return;
+
+			case 'html':
+
+				if ($this->sendMultipart === false)
+				{
+					$hdr .= 'Content-Type: text/html; charset=' . $this->charset . $this->newline
+							. 'Content-Transfer-Encoding: quoted-printable';
+				}
+				else
+				{
+					$boundary = uniqid('B_ALT_', true);
+					$hdr     .= 'Content-Type: multipart/alternative; boundary="' . $boundary . '"';
+
+					$body .= $this->getMimeMessage() . $this->newline . $this->newline
+							. '--' . $boundary . $this->newline
+							. 'Content-Type: text/plain; charset=' . $this->charset . $this->newline
+							. 'Content-Transfer-Encoding: ' . $this->getEncoding() . $this->newline . $this->newline
+							. $this->getAltMessage() . $this->newline . $this->newline
+							. '--' . $boundary . $this->newline
+							. 'Content-Type: text/html; charset=' . $this->charset . $this->newline
+							. 'Content-Transfer-Encoding: quoted-printable' . $this->newline . $this->newline;
+				}
+
+				$this->finalBody = $body . $this->prepQuotedPrintable($this->body) . $this->newline . $this->newline;
+
+				if ($this->getProtocol() === 'mail')
+				{
+					$this->headerStr .= $hdr;
+				}
+				else
+				{
+					$this->finalBody = $hdr . $this->newline . $this->newline . $this->finalBody;
+				}
+
+				if ($this->sendMultipart !== false)
+				{
+					$this->finalBody .= '--' . $boundary . '--';
+				}
+
+				return;
+
+			case 'plain-attach':
+
+				$boundary = uniqid('B_ATC_', true);
+				$hdr     .= 'Content-Type: multipart/mixed; boundary="' . $boundary . '"';
+
+				if ($this->getProtocol() === 'mail')
+				{
+					$this->headerStr .= $hdr;
+				}
+
+				$body .= $this->getMimeMessage() . $this->newline
+						. $this->newline
+						. '--' . $boundary . $this->newline
+						. 'Content-Type: text/plain; charset=' . $this->charset . $this->newline
+						. 'Content-Transfer-Encoding: ' . $this->getEncoding() . $this->newline
+						. $this->newline
+						. $this->body . $this->newline . $this->newline;
+
+				$this->appendAttachments($body, $boundary);
+
+				break;
+			case 'html-attach':
+
+				$alt_boundary  = uniqid('B_ALT_', true);
+				$last_boundary = null;
+
+				if ($this->attachmentsHaveMultipart('mixed'))
+				{
+					$atc_boundary  = uniqid('B_ATC_', true);
+					$hdr          .= 'Content-Type: multipart/mixed; boundary="' . $atc_boundary . '"';
+					$last_boundary = $atc_boundary;
+				}
+
+				if ($this->attachmentsHaveMultipart('related'))
+				{
+					$rel_boundary        = uniqid('B_REL_', true);
+					$rel_boundary_header = 'Content-Type: multipart/related; boundary="' . $rel_boundary . '"';
+
+					if (isset($last_boundary))
+					{
+						$body .= '--' . $last_boundary . $this->newline . $rel_boundary_header;
+					}
+					else
+					{
+						$hdr .= $rel_boundary_header;
+					}
+
+					$last_boundary = $rel_boundary;
+				}
+
+				if ($this->getProtocol() === 'mail')
+				{
+					$this->headerStr .= $hdr;
+				}
+
+				static::strlen($body) && $body .= $this->newline . $this->newline;
+				$body                          .= $this->getMimeMessage() . $this->newline . $this->newline
+						. '--' . $last_boundary . $this->newline
+						. 'Content-Type: multipart/alternative; boundary="' . $alt_boundary . '"' . $this->newline . $this->newline
+						. '--' . $alt_boundary . $this->newline
+						. 'Content-Type: text/plain; charset=' . $this->charset . $this->newline
+						. 'Content-Transfer-Encoding: ' . $this->getEncoding() . $this->newline . $this->newline
+						. $this->getAltMessage() . $this->newline . $this->newline
+						. '--' . $alt_boundary . $this->newline
+						. 'Content-Type: text/html; charset=' . $this->charset . $this->newline
+						. 'Content-Transfer-Encoding: quoted-printable' . $this->newline . $this->newline
+						. $this->prepQuotedPrintable($this->body) . $this->newline . $this->newline
+						. '--' . $alt_boundary . '--' . $this->newline . $this->newline;
+
+				if (! empty($rel_boundary))
+				{
+					$body .= $this->newline . $this->newline;
+					$this->appendAttachments($body, $rel_boundary, 'related');
+				}
+
+				// multipart/mixed attachments
+				if (! empty($atc_boundary))
+				{
+					$body .= $this->newline . $this->newline;
+					$this->appendAttachments($body, $atc_boundary, 'mixed');
+				}
+
+				break;
+		}
+
+		$this->finalBody = ($this->getProtocol() === 'mail') ? $body : $hdr . $this->newline . $this->newline . $body;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Prepares attachment string
+	 *
+	 * @param string      &$body     Message body to append to
+	 * @param string      $boundary  Multipart boundary
+	 * @param string|null $multipart When provided, only attachments of this type will be processed
+	 *
+	 * @return string
+	 */
+	protected function appendAttachments(&$body, $boundary, $multipart = null)
+	{
+		for ($i = 0, $c = count($this->attachments); $i < $c; $i ++)
+		{
+			if (isset($multipart) && $this->attachments[$i]['multipart'] !== $multipart)
+			{
+				continue;
+			}
+
+			$name = isset($this->attachments[$i]['name'][1]) ? $this->attachments[$i]['name'][1] : basename($this->attachments[$i]['name'][0]);
+
+			$body .= '--' . $boundary . $this->newline
+					. 'Content-Type: ' . $this->attachments[$i]['type'] . '; name="' . $name . '"' . $this->newline
+					. 'Content-Disposition: ' . $this->attachments[$i]['disposition'] . ';' . $this->newline
+					. 'Content-Transfer-Encoding: base64' . $this->newline
+					. (empty($this->attachments[$i]['cid']) ? '' : 'Content-ID: <' . $this->attachments[$i]['cid'] . '>' . $this->newline)
+					. $this->newline
+					. $this->attachments[$i]['content'] . $this->newline;
+		}
+
+		// $name won't be set if no attachments were appended,
+		// and therefore a boundary wouldn't be necessary
+		empty($name) || $body .= '--' . $boundary . '--';
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Prep Quoted Printable
+	 *
+	 * Prepares string for Quoted-Printable Content-Transfer-Encoding
+	 * Refer to RFC 2045 http://www.ietf.org/rfc/rfc2045.txt
+	 *
+	 * @param string $str
+	 *
+	 * @return string
+	 */
+	protected function prepQuotedPrintable($str)
+	{
+		// ASCII code numbers for "safe" characters that can always be
+		// used literally, without encoding, as described in RFC 2049.
+		// http://www.ietf.org/rfc/rfc2049.txt
+		static $ascii_safe_chars = [
+			// ' (  )   +   ,   -   .   /   :   =   ?
+			39,
+			40,
+			41,
+			43,
+			44,
+			45,
+			46,
+			47,
+			58,
+			61,
+			63,
+			// numbers
+			48,
+			49,
+			50,
+			51,
+			52,
+			53,
+			54,
+			55,
+			56,
+			57,
+			// upper-case letters
+			65,
+			66,
+			67,
+			68,
+			69,
+			70,
+			71,
+			72,
+			73,
+			74,
+			75,
+			76,
+			77,
+			78,
+			79,
+			80,
+			81,
+			82,
+			83,
+			84,
+			85,
+			86,
+			87,
+			88,
+			89,
+			90,
+			// lower-case letters
+			97,
+			98,
+			99,
+			100,
+			101,
+			102,
+			103,
+			104,
+			105,
+			106,
+			107,
+			108,
+			109,
+			110,
+			111,
+			112,
+			113,
+			114,
+			115,
+			116,
+			117,
+			118,
+			119,
+			120,
+			121,
+			122,
+		];
+
+		// We are intentionally wrapping so mail servers will encode characters
+		// properly and MUAs will behave, so {unwrap} must go!
+		$str = str_replace(['{unwrap}', '{/unwrap}'], '', $str);
+
+		// RFC 2045 specifies CRLF as "\r\n".
+		// However, many developers choose to override that and violate
+		// the RFC rules due to (apparently) a bug in MS Exchange,
+		// which only works with "\n".
+		if ($this->CRLF === "\r\n")
+		{
+			return quoted_printable_encode($str);
+		}
+
+		// Reduce multiple spaces & remove nulls
+		$str = preg_replace(['| +|', '/\x00+/'], [' ', ''], $str);
+
+		// Standardize newlines
+		if (strpos($str, "\r") !== false)
+		{
+			$str = str_replace(["\r\n", "\r"], "\n", $str);
+		}
+
+		$escape = '=';
+		$output = '';
+
+		foreach (explode("\n", $str) as $line)
+		{
+			$length = static::strlen($line);
+			$temp   = '';
+
+			// Loop through each character in the line to add soft-wrap
+			// characters at the end of a line " =\r\n" and add the newly
+			// processed line(s) to the output (see comment on $crlf class property)
+			for ($i = 0; $i < $length; $i ++)
+			{
+				// Grab the next character
+				$char  = $line[$i];
+				$ascii = ord($char);
+
+				// Convert spaces and tabs but only if it's the end of the line
+				if ($ascii === 32 || $ascii === 9)
+				{
+					if ($i === ($length - 1))
+					{
+						$char = $escape . sprintf('%02s', dechex($ascii));
+					}
+				}
+				// DO NOT move this below the $ascii_safe_chars line!
+				//
+				// = (equals) signs are allowed by RFC2049, but must be encoded
+				// as they are the encoding delimiter!
+				elseif ($ascii === 61)
+				{
+					$char = $escape . strtoupper(sprintf('%02s', dechex($ascii)));  // =3D
+				}
+				elseif (! in_array($ascii, $ascii_safe_chars, true))
+				{
+					$char = $escape . strtoupper(sprintf('%02s', dechex($ascii)));
+				}
+
+				// If we're at the character limit, add the line to the output,
+				// reset our temp variable, and keep on chuggin'
+				if ((static::strlen($temp) + static::strlen($char)) >= 76)
+				{
+					$output .= $temp . $escape . $this->CRLF;
+					$temp    = '';
+				}
+
+				// Add the character to our temporary line
+				$temp .= $char;
+			}
+
+			// Add our completed line to the output
+			$output .= $temp . $this->CRLF;
+		}
+
+		// get rid of extra CRLF tacked onto the end
+		return static::substr($output, 0, static::strlen($this->CRLF) * -1);
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Prep Q Encoding
+	 *
+	 * Performs "Q Encoding" on a string for use in email headers.
+	 * It's related but not identical to quoted-printable, so it has its
+	 * own method.
+	 *
+	 * @param string $str
+	 *
+	 * @return string
+	 */
+	protected function prepQEncoding($str)
+	{
+		$str = str_replace(["\r", "\n"], '', $str);
+
+		if ($this->charset === 'UTF-8')
+		{
+			// Note: We used to have mb_encode_mimeheader() as the first choice
+			//       here, but it turned out to be buggy and unreliable. DO NOT
+			//       re-add it! -- Narf
+			if (extension_loaded('iconv'))
+			{
+				$output = @iconv_mime_encode(
+								'', $str, [
+									'scheme'           => 'Q',
+									'line-length'      => 76,
+									'input-charset'    => $this->charset,
+									'output-charset'   => $this->charset,
+									'line-break-chars' => $this->CRLF,
+								]);
+
+				// There are reports that iconv_mime_encode() might fail and return FALSE
+				if ($output !== false)
+				{
+					// iconv_mime_encode() will always put a header field name.
+					// We've passed it an empty one, but it still prepends our
+					// encoded string with ': ', so we need to strip it.
+					return static::substr($output, 2);
+				}
+
+				$chars = iconv_strlen($str, 'UTF-8');
+			}
+			elseif (extension_loaded('mbstring'))
+			{
+				$chars = mb_strlen($str, 'UTF-8');
+			}
+		}
+
+		// We might already have this set for UTF-8
+		isset($chars) || $chars = static::strlen($str);
+
+		$output = '=?' . $this->charset . '?Q?';
+		for ($i = 0, $length = static::strlen($output); $i < $chars; $i ++)
+		{
+			$chr = ($this->charset === 'UTF-8' && ICONV_ENABLED === true) ? '=' . implode('=', str_split(strtoupper(bin2hex(iconv_substr($str, $i, 1, $this->charset))), 2)) : '=' . strtoupper(bin2hex($str[$i]));
+
+			// RFC 2045 sets a limit of 76 characters per line.
+			// We'll append ?= to the end of each line though.
+			if ($length + ($l = static::strlen($chr)) > 74)
+			{
+				$output .= '?=' . $this->CRLF // EOL
+						. ' =?' . $this->charset . '?Q?' . $chr; // New line
+				$length  = 6 + static::strlen($this->charset) + $l; // Reset the length for the new line
+			}
+			else
+			{
+				$output .= $chr;
+				$length += $l;
+			}
+		}
+
+		// End the header
+		return $output . '?=';
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Send the Message
+	 *
+	 * @param boolean $autoClear
+	 *
+	 * @return boolean
+	 */
+	public function send(Message $message, bool $autoClear = true, bool $reallySend = true)
+	{
+		if (! isset($this->headers['From']) && ! empty($this->fromEmail))
+		{
+			$this->setFrom($this->fromEmail, $this->fromName);
+		}
+
+		if (! isset($this->headers['From']))
+		{
+			throw MailerException::forNoFrom();
+		}
+
+		if ($this->replyToFlag === false)
+		{
+			$this->setReplyTo($this->headers['From']);
+		}
+
+		if (empty($this->recipients) && ! isset($this->headers['To']) && empty($this->BCCArray) && ! isset($this->headers['Bcc']) && ! isset($this->headers['Cc'])
+		)
+		{
+			throw MailerException::forNoRecipients();
+		}
+
+		$this->buildHeaders();
+
+		if ($this->BCCBatchMode && count($this->BCCArray) > $this->BCCBatchSize)
+		{
+			$this->batchBCCSend();
+
+			if ($autoClear)
+			{
+				$this->clear();
+			}
+
+			return true;
+		}
+
+		$this->buildMessage();
+		$result = $this->spoolEmail();
+
+		if ($result && $autoClear)
+		{
+			$this->clear();
+		}
+
+		return $result;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Batch Bcc Send. Sends groups of BCCs in batches
+	 */
+	public function batchBCCSend()
+	{
+		$float = $this->BCCBatchSize - 1;
+		$set   = '';
+		$chunk = [];
+
+		for ($i = 0, $c = count($this->BCCArray); $i < $c; $i ++)
+		{
+			if (isset($this->BCCArray[$i]))
+			{
+				$set .= ', ' . $this->BCCArray[$i];
+			}
+
+			if ($i === $float)
+			{
+				$chunk[] = static::substr($set, 1);
+				$float  += $this->BCCBatchSize;
+				$set     = '';
+			}
+
+			if ($i === $c - 1)
+			{
+				$chunk[] = static::substr($set, 1);
+			}
+		}
+
+		for ($i = 0, $c = count($chunk); $i < $c; $i ++)
+		{
+			unset($this->headers['Bcc']);
+
+			$bcc = $this->cleanEmail($this->stringToArray($chunk[$i]));
+
+			if ($this->protocol !== 'smtp')
+			{
+				$this->setHeader('Bcc', implode(', ', $bcc));
+			}
+			else
+			{
+				$this->BCCArray = $bcc;
+			}
+
+			$this->buildMessage();
+			$this->spoolEmail();
+		}
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Unwrap special elements
+	 */
+	protected function unwrapSpecials()
+	{
+		$this->finalBody = preg_replace_callback(
+				'/\{unwrap\}(.*?)\{\/unwrap\}/si', [
+					$this,
+					'removeNLCallback',
+				], $this->finalBody
+		);
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Strip line-breaks via callback
+	 *
+	 * @param string $matches
+	 *
+	 * @return string
+	 */
+	protected function removeNLCallback($matches)
+	{
+		if (strpos($matches[1], "\r") !== false || strpos($matches[1], "\n") !== false)
+		{
+			$matches[1] = str_replace(["\r\n", "\r", "\n"], '', $matches[1]);
+		}
+
+		return $matches[1];
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Spool mail to the mail server
+	 *
+	 * @return boolean
+	 */
+	protected function spoolEmail()
+	{
+		$this->unwrapSpecials();
+
+		$protocol = $this->getProtocol();
+		$method   = 'sendWith' . ucfirst($protocol);
+		try
+		{
+			$success = $this->$method();
+		}
+		catch (\ErrorException $e)
+		{
+			$success = false;
+			$this->logger->error('Mailer: ' . $method . ' throwed ' . $e->getMessage());
+		}
+
+		if (! $success)
+		{
+			throw MailerException::forSendFailure($protocol === 'mail' ? 'PHPMail' : ucfirst($protocol));
+		}
+
+		$this->setErrorMessage(lang('Mailer.sent', [$protocol]));
+
+		return true;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Validate email for shell
+	 *
+	 * Applies stricter, shell-safe validation to email addresses.
+	 * Introduced to prevent RCE via sendmail's -f option.
+	 *
+	 * @see     https://github.com/codeigniter4/CodeIgniter/issues/4963
+	 * @see     https://gist.github.com/Zenexer/40d02da5e07f151adeaeeaa11af9ab36
+	 * @license https://creativecommons.org/publicdomain/zero/1.0/    CC0 1.0, Public Domain
+	 *
+	 * Credits for the base concept go to Paul Buonopane <paul@namepros.com>
+	 *
+	 * @param string &$email
+	 *
+	 * @return boolean
+	 */
+	protected function validateEmailForShell(&$email)
+	{
+		if (function_exists('idn_to_ascii') && $atpos = strpos($email, '@'))
+		{
+			$email = static::substr($email, 0, ++ $atpos) . idn_to_ascii(
+							static::substr($email, $atpos), 0, INTL_IDNA_VARIANT_UTS46
+			);
+		}
+
+		return (filter_var($email, FILTER_VALIDATE_EMAIL) === $email && preg_match('#\A[a-z0-9._+-]+@[a-z0-9.-]{1,253}\z#i', $email));
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Send using mail()
+	 *
+	 * @return boolean
+	 */
+	protected function sendWithMail()
+	{
+		if (is_array($this->recipients))
+		{
+			$this->recipients = implode(', ', $this->recipients);
+		}
+
+		// _validate_email_for_shell() below accepts by reference,
+		// so this needs to be assigned to a variable
+		$from = $this->cleanEmail($this->headers['Return-Path']);
+
+		if (! $this->validateEmailForShell($from))
+		{
+			return mail($this->recipients, $this->subject, $this->finalBody, $this->headerStr);
+		}
+
+		// most documentation of sendmail using the "-f" flag lacks a space after it, however
+		// we've encountered servers that seem to require it to be in place.
+		return mail($this->recipients, $this->subject, $this->finalBody, $this->headerStr, '-f ' . $from);
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Send using Sendmail
+	 *
+	 * @return boolean
+	 */
+	protected function sendWithSendmail()
+	{
+		// _validate_email_for_shell() below accepts by reference,
+		// so this needs to be assigned to a variable
+		$from = $this->cleanEmail($this->headers['From']);
+		if ($this->validateEmailForShell($from))
+		{
+			$from = '-f ' . $from;
+		}
+		else
+		{
+			$from = '';
+		}
+
+		// is popen() enabled?
+		if (! function_usable('popen') || false === ($fp = @popen($this->mailPath . ' -oi ' . $from . ' -t', 'w')))
+		{
+			// server probably has popen disabled, so nothing we can do to get a verbose error.
+			return false;
+		}
+
+		fputs($fp, $this->headerStr);
+		fputs($fp, $this->finalBody);
+
+		$status = pclose($fp);
+
+		if ($status !== 0)
+		{
+			throw MailerException::forNosocket($status);
+		}
+
+		return true;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Send using SMTP
+	 *
+	 * @return boolean
+	 */
+	protected function sendWithSmtp()
+	{
+		if ($this->SMTPHost === '')
+		{
+			throw MailerException::forNoHostname();
+		}
+
+		if (! $this->SMTPConnect() || ! $this->SMTPAuthenticate())
+		{
+			return false;
+		}
+
+		if (! $this->sendCommand('from', $this->cleanEmail($this->headers['From'])))
+		{
+			$this->SMTPEnd();
+
+			return false;
+		}
+
+		foreach ($this->recipients as $val)
+		{
+			if (! $this->sendCommand('to', $val))
+			{
+				$this->SMTPEnd();
+
+				return false;
+			}
+		}
+
+		foreach ($this->CCArray as $val)
+		{
+			if ($val !== '' && ! $this->sendCommand('to', $val))
+			{
+				$this->SMTPEnd();
+
+				return false;
+			}
+		}
+
+		foreach ($this->BCCArray as $val)
+		{
+			if ($val !== '' && ! $this->sendCommand('to', $val))
+			{
+				$this->SMTPEnd();
+
+				return false;
+			}
+		}
+
+		if (! $this->sendCommand('data'))
+		{
+			$this->SMTPEnd();
+
+			return false;
+		}
+
+		// perform dot transformation on any lines that begin with a dot
+		$this->sendData($this->headerStr . preg_replace('/^\./m', '..$1', $this->finalBody));
+
+		$this->sendData('.');
+		$reply = $this->getSMTPData();
+		$this->setErrorMessage($reply);
+
+		$this->SMTPEnd();
+
+		if (strpos($reply, '250') !== 0)
+		{
+			throw MailerException::forSMTPError($reply);
+		}
+
+		return true;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * SMTP End
+	 *
+	 * Shortcut to send RSET or QUIT depending on keep-alive
+	 */
+	protected function SMTPEnd()
+	{
+		$this->sendCommand($this->SMTPKeepAlive ? 'reset' : 'quit');
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * SMTP Connect
+	 *
+	 * @return string
+	 */
+	protected function SMTPConnect()
+	{
+		if (is_resource($this->SMTPConnect))
+		{
+			return true;
+		}
+
+		$ssl = ($this->SMTPCrypto === 'ssl') ? 'ssl://' : '';
+
+		$this->SMTPConnect = fsockopen(
+				$ssl . $this->SMTPHost, $this->SMTPPort, $errno, $errstr, $this->SMTPTimeout
+		);
+
+		if (! is_resource($this->SMTPConnect))
+		{
+			throw MailerException::forSMTPError($errno . ' ' . $errstr);
+		}
+
+		stream_set_timeout($this->SMTPConnect, $this->SMTPTimeout);
+		$this->setErrorMessage($this->getSMTPData());
+
+		if ($this->SMTPCrypto === 'tls')
+		{
+			$this->sendCommand('hello');
+			$this->sendCommand('starttls');
+
+			$crypto = stream_socket_enable_crypto($this->SMTPConnect, true, STREAM_CRYPTO_METHOD_TLS_CLIENT);
+
+			if ($crypto !== true)
+			{
+				throw MailerException::forSMTPError($this->getSMTPData());
+			}
+		}
+
+		return $this->sendCommand('hello');
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Send SMTP command
+	 *
+	 * @param string $cmd
+	 * @param string $data
+	 *
+	 * @return boolean
+	 */
+	protected function sendCommand($cmd, $data = '')
+	{
+		switch ($cmd)
+		{
+			case 'hello':
+				if ($this->SMTPAuth || $this->getEncoding() === '8bit')
+				{
+					$this->sendData('EHLO ' . $this->getHostname());
+				}
+				else
+				{
+					$this->sendData('HELO ' . $this->getHostname());
+				}
+
+				$resp = 250;
+				break;
+			case 'starttls':
+				$this->sendData('STARTTLS');
+				$resp = 220;
+				break;
+			case 'from':
+				$this->sendData('MAIL FROM:<' . $data . '>');
+				$resp = 250;
+				break;
+			case 'to':
+				if ($this->DSN)
+				{
+					$this->sendData('RCPT TO:<' . $data . '> NOTIFY=SUCCESS,DELAY,FAILURE ORCPT=rfc822;' . $data);
+				}
+				else
+				{
+					$this->sendData('RCPT TO:<' . $data . '>');
+				}
+				$resp = 250;
+				break;
+			case 'data':
+				$this->sendData('DATA');
+				$resp = 354;
+				break;
+			case 'reset':
+				$this->sendData('RSET');
+				$resp = 250;
+				break;
+			case 'quit':
+				$this->sendData('QUIT');
+				$resp = 221;
+				break;
+		}
+
+		$reply = $this->getSMTPData();
+
+		$this->debugMessage[] = '<pre>' . $cmd . ': ' . $reply . '</pre>';
+
+		if ((int) static::substr($reply, 0, 3) !== $resp)
+		{
+			throw MailerException::forSMTPError($reply);
+		}
+
+		if ($cmd === 'quit')
+		{
+			fclose($this->SMTPConnect);
+		}
+
+		return true;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * SMTP Authenticate
+	 *
+	 * @return boolean
+	 */
+	protected function SMTPAuthenticate()
+	{
+		if (! $this->SMTPAuth)
+		{
+			return true;
+		}
+
+		if ($this->SMTPUser === '' && $this->SMTPPass === '')
+		{
+			throw MailerException::forNoSMTPAuth();
+		}
+
+		$this->sendData('AUTH LOGIN');
+		$reply = $this->getSMTPData();
+
+		if (strpos($reply, '503') === 0)    // Already authenticated
+		{
+			return true;
+		}
+		elseif (strpos($reply, '334') !== 0)
+		{
+			throw MailerException::forFailedSMTPLogin($reply);
+		}
+
+		$this->sendData(base64_encode($this->SMTPUser));
+		$reply = $this->getSMTPData();
+
+		if (strpos($reply, '334') !== 0)
+		{
+			throw MailerException::forSMTPAuthUsername($reply);
+		}
+
+		$this->sendData(base64_encode($this->SMTPPass));
+		$reply = $this->getSMTPData();
+
+		if (strpos($reply, '235') !== 0)
+		{
+			throw MailerException::forSMTPAuthPassword($reply);
+		}
+
+		if ($this->SMTPKeepAlive)
+		{
+			$this->SMTPAuth = false;
+		}
+
+		return true;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Send SMTP data
+	 *
+	 * @param string $data
+	 *
+	 * @return boolean
+	 */
+	protected function sendData($data)
+	{
+		$data .= $this->newline;
+		for ($written = $timestamp = 0, $length = static::strlen($data); $written < $length; $written += $result)
+		{
+			if (($result = fwrite($this->SMTPConnect, static::substr($data, $written))) === false)
+			{
+				break;
+			}
+			// See https://bugs.php.net/bug.php?id=39598 and http://php.net/manual/en/function.fwrite.php#96951
+			elseif ($result === 0)
+			{
+				if ($timestamp === 0)
+				{
+					$timestamp = time();
+				}
+				elseif ($timestamp < (time() - $this->SMTPTimeout))
+				{
+					$result = false;
+					break;
+				}
+
+				usleep(250000);
+				continue;
+			}
+			else
+			{
+				$timestamp = 0;
+			}
+		}
+
+		if ($result === false)
+		{
+			throw MailerException::forSMTPDataFailure($data);
+		}
+
+		return true;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Get SMTP data
+	 *
+	 * @return string
+	 */
+	protected function getSMTPData()
+	{
+		$data = '';
+
+		while ($str = fgets($this->SMTPConnect, 512))
+		{
+			$data .= $str;
+
+			if ($str[3] === ' ')
+			{
+				break;
+			}
+		}
+
+		return $data;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Get Hostname
+	 *
+	 * There are only two legal types of hostname - either a fully
+	 * qualified domain name (eg: "mail.example.com") or an IP literal
+	 * (eg: "[1.2.3.4]").
+	 *
+	 * @link https://tools.ietf.org/html/rfc5321#section-2.3.5
+	 * @link http://cbl.abuseat.org/namingproblems.html
+	 *
+	 * @return string
+	 */
+	protected function getHostname()
+	{
+		if (isset($_SERVER['SERVER_NAME']))
+		{
+			return $_SERVER['SERVER_NAME'];
+		}
+
+		return isset($_SERVER['SERVER_ADDR']) ? '[' . $_SERVER['SERVER_ADDR'] . ']' : '[127.0.0.1]';
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Get Debug Message
+	 *
+	 * @param array $include List of raw data chunks to include in the output
+	 *                       Valid options are: 'headers', 'subject', 'body'
+	 *
+	 * @return string
+	 */
+	public function printDebugger($include = ['headers', 'subject', 'body'])
+	{
+		$msg = implode('', $this->debugMessage);
+
+		// Determine which parts of our raw data needs to be printed
+		$raw_data                      = '';
+		is_array($include) || $include = [$include];
+
+		in_array('headers', $include, true) && $raw_data  = htmlspecialchars($this->headerStr) . "\n";
+		in_array('subject', $include, true) && $raw_data .= htmlspecialchars($this->subject) . "\n";
+		in_array('body', $include, true) && $raw_data    .= htmlspecialchars($this->finalBody);
+
+		return $msg . ($raw_data === '' ? '' : '<pre>' . $raw_data . '</pre>');
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Set Message
+	 *
+	 * @param string $msg
+	 */
+	protected function setErrorMessage($msg)
+	{
+		$this->debugMessage[] = $msg . '<br />';
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Mime Types
+	 *
+	 * @param string $ext
+	 *
+	 * @return string
+	 */
+	protected function mimeTypes($ext = '')
+	{
+		$mime = Mimes::guessTypeFromExtension(strtolower($ext));
+
+		return ! empty($mime) ? $mime : 'application/x-unknown-content-type';
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Destructor
+	 */
+	public function __destruct()
+	{
+		is_resource($this->SMTPConnect) && $this->sendCommand('quit');
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Byte-safe strlen()
+	 *
+	 * @param string $str
+	 *
+	 * @return integer
+	 */
+	protected static function strlen($str)
+	{
+		return (static::$func_overload) ? mb_strlen($str, '8bit') : strlen($str);
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Byte-safe substr()
+	 *
+	 * @param string       $str
+	 * @param integer      $start
+	 * @param integer|null $length
+	 *
+	 * @return string
+	 */
+	protected static function substr($str, $start, $length = null)
+	{
+		if (static::$func_overload)
+		{
+			return mb_substr($str, $start, $length, '8bit');
+		}
+
+		return isset($length) ? substr($str, $start, $length) : substr($str, $start);
+	}
+
+}
diff --git a/system/Mailer/Handlers/SendmailHandler.php b/system/Mailer/Handlers/SendmailHandler.php
new file mode 100644
index 000000000000..9194552a41c0
--- /dev/null
+++ b/system/Mailer/Handlers/SendmailHandler.php
@@ -0,0 +1,1638 @@
+<?php
+namespace CodeIgniter\Mailer\Handlers;
+
+/**
+ * CodeIgniter
+ *
+ * An open source application development framework for PHP
+ *
+ * This content is released under the MIT License (MIT)
+ *
+ * Copyright (c) 2014 - 2018, British Columbia Institute of Technology
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ * @package    CodeIgniter
+ * @author     EllisLab Dev Team
+ * @copyright  Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
+ * @copyright  Copyright (c) 2014 - 2018, British Columbia Institute of Technology (http://bcit.ca/)
+ * @license    http://opensource.org/licenses/MIT    MIT License
+ * @link       https://codeigniter.com
+ * @since      Version 1.0.0
+ * @filesource
+ */
+
+use CodeIgniter\Mailer\Message;
+use CodeIgniter\Mailer\Exceptions\MailerException;
+use Config\Mimes;
+use Psr\Log\LoggerAwareTrait;
+
+/**
+ * CodeIgniter Mailer Class
+ *
+ * Permits email to be sent using Mail, Sendmail, or SMTP.
+ *
+ * @package    CodeIgniter
+ * @subpackage Libraries
+ * @category   Libraries
+ * @author     EllisLab Dev Team
+ * @link       https://codeigniter.com/user_guide/libraries/email.html
+ */
+class SendmailHandler extends BaseHandler
+{
+
+	/**
+	 * Message format.
+	 *
+	 * @var string 'text' or 'html'
+	 */
+	public $mailType = 'text';
+
+	/**
+	 * Character set (default: utf-8)
+	 *
+	 * @var string
+	 */
+	public $charset = 'utf-8';
+
+	/**
+	 * Alternative message (for HTML messages only)
+	 *
+	 * @var string
+	 */
+	public $altMessage = '';
+
+	/**
+	 * Whether to validate e-mail addresses.
+	 *
+	 * @var boolean
+	 */
+	public $validate = true;
+
+	/**
+	 * X-Priority header value.
+	 *
+	 * @var integer 1-5
+	 */
+	public $priority = 3;            // Default priority (1 - 5)
+
+	/**
+	 * Newline character sequence.
+	 * Use "\r\n" to comply with RFC 822.
+	 *
+	 * @link http://www.ietf.org/rfc/rfc822.txt
+	 * @var  string "\r\n" or "\n"
+	 */
+	public $newline = "\n";            // Default newline. "\r\n" or "\n" (Use "\r\n" to comply with RFC 822)
+
+	/**
+	 * CRLF character sequence
+	 *
+	 * RFC 2045 specifies that for 'quoted-printable' encoding,
+	 * "\r\n" must be used. However, it appears that some servers
+	 * (even on the receiving end) don't handle it properly and
+	 * switching to "\n", while improper, is the only solution
+	 * that seems to work for all environments.
+	 *
+	 * @link http://www.ietf.org/rfc/rfc822.txt
+	 * @var  string
+	 */
+	public $CRLF = "\n";
+
+	/**
+	 * Whether to use Delivery Status Notification.
+	 *
+	 * @var boolean
+	 */
+	public $DSN = false;
+
+	/**
+	 * Whether to send multipart alternatives.
+	 * Yahoo! doesn't seem to like these.
+	 *
+	 * @var boolean
+	 */
+	public $sendMultipart = true;
+
+	/**
+	 * Whether to send messages to BCC recipients in batches.
+	 *
+	 * @var boolean
+	 */
+	public $BCCBatchMode = false;
+
+	/**
+	 * BCC Batch max number size.
+	 *
+	 * @see self::$BCCBatchMode
+	 * @var integer
+	 */
+	public $BCCBatchSize = 200;
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Subject header
+	 *
+	 * @var string
+	 */
+	protected $subject = '';
+
+	/**
+	 * Message body
+	 *
+	 * @var string
+	 */
+	protected $body = '';
+
+	/**
+	 * Final message body to be sent.
+	 *
+	 * @var string
+	 */
+	protected $finalBody = '';
+
+	/**
+	 * Final headers to send
+	 *
+	 * @var string
+	 */
+	protected $headerStr = '';
+
+	/**
+	 * SMTP Connection socket placeholder
+	 *
+	 * @var resource
+	 */
+	protected $SMTPConnect = '';
+
+	/**
+	 * Mail encoding
+	 *
+	 * @var string '8bit' or '7bit'
+	 */
+	protected $encoding = '8bit';
+
+	/**
+	 * Whether to send a Reply-To header
+	 *
+	 * @var boolean
+	 */
+	protected $replyToFlag = false;
+
+	/**
+	 * Debug messages
+	 *
+	 * @see self::printDebugger()
+	 * @var array
+	 */
+	protected $debugMessage = [];
+
+	/**
+	 * Recipients
+	 *
+	 * @var array
+	 */
+	protected $recipients = [];
+
+	/**
+	 * CC Recipients
+	 *
+	 * @var array
+	 */
+	protected $CCArray = [];
+
+	/**
+	 * BCC Recipients
+	 *
+	 * @var array
+	 */
+	protected $BCCArray = [];
+
+	/**
+	 * Message headers
+	 *
+	 * @var array
+	 */
+	protected $headers = [];
+
+	/**
+	 * Attachment data
+	 *
+	 * @var array
+	 */
+	protected $attachments = [];
+
+	/**
+	 * Valid $protocol values
+	 *
+	 * @see self::$protocol
+	 * @var array
+	 */
+	protected $protocols = [
+		'mail',
+		'sendmail',
+		'smtp',
+	];
+
+	/**
+	 * Base charsets
+	 *
+	 * Character sets valid for 7-bit encoding,
+	 * excluding language suffix.
+	 *
+	 * @var array
+	 */
+	protected $baseCharsets = [
+		'us-ascii',
+		'iso-2022-',
+	];
+
+	/**
+	 * Bit depths
+	 *
+	 * Valid mail encodings
+	 *
+	 * @see self::$encoding
+	 * @var array
+	 */
+	protected $bitDepths = [
+		'7bit',
+		'8bit',
+	];
+
+	/**
+	 * $priority translations
+	 *
+	 * Actual values to send with the X-Priority header
+	 *
+	 * @var array
+	 */
+	protected $priorities = [
+		1 => '1 (Highest)',
+		2 => '2 (High)',
+		3 => '3 (Normal)',
+		4 => '4 (Low)',
+		5 => '5 (Lowest)',
+	];
+
+	/**
+	 * mbstring.func_overload flag
+	 *
+	 * @var boolean
+	 */
+	protected static $func_overload;
+
+	/**
+	 * Logger instance to record error messages and awarnings.
+	 *
+	 * @var \PSR\Log\LoggerInterface
+	 */
+	protected $logger;
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Constructor - Sets Preferences
+	 *
+	 * The constructor can be passed an array of config values
+	 *
+	 * @param array|null $config
+	 */
+	public function __construct($config = null)
+	{
+		$this->protocol = 'sendmail';
+		$this->initialize($config);
+
+		log_message('info', 'Mailer Class Initialized');
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Initialize preferences
+	 *
+	 * @param array|\Config\Mailer $config
+	 *
+	 * @return $this
+	 */
+	public function initialize($config)
+	{
+		$this->clear();
+
+		if ($config instanceof \Config\Mailer)
+		{
+			$config = get_object_vars($config);
+		}
+
+		foreach (get_class_vars(get_class($this)) as $key => $value)
+		{
+			if (property_exists($this, $key) && isset($config[$key]))
+			{
+				$method = 'set' . ucfirst($key);
+
+				if (method_exists($this, $method))
+				{
+					$this->$method($config[$key]);
+				}
+				else
+				{
+					$this->$key = $config[$key];
+				}
+			}
+		}
+
+		$this->charset  = strtoupper($this->charset);
+		$this->SMTPAuth = isset($this->SMTPUser[0], $this->SMTPPass[0]);
+
+		return $this;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Initialize the Data
+	 *
+	 * @param boolean $clearAttachments
+	 *
+	 * @return $this
+	 */
+	public function clear($clearAttachments = false)
+	{
+		$this->subject      = '';
+		$this->body         = '';
+		$this->finalBody    = '';
+		$this->headerStr    = '';
+		$this->replyToFlag  = false;
+		$this->recipients   = [];
+		$this->CCArray      = [];
+		$this->BCCArray     = [];
+		$this->headers      = [];
+		$this->debugMessage = [];
+
+		//      $this->setHeader('Date', $this->setDate());
+
+		if ($clearAttachments !== false)
+		{
+			$this->attachments = [];
+		}
+
+		return $this;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Build final headers
+	 */
+	protected function buildHeaders()
+	{
+		$this->setHeader('User-Agent', $this->userAgent);
+		$this->setHeader('X-Sender', $this->cleanEmail($this->headers['From']));
+		$this->setHeader('X-Mailer', $this->userAgent);
+		$this->setHeader('X-Priority', $this->priorities[$this->priority]);
+		$this->setHeader('Message-ID', $this->getMessageID());
+		$this->setHeader('Mime-Version', '1.0');
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Write Headers as a string
+	 */
+	protected function writeHeaders()
+	{
+		if ($this->protocol === 'mail')
+		{
+			if (isset($this->headers['Subject']))
+			{
+				$this->subject = $this->headers['Subject'];
+				unset($this->headers['Subject']);
+			}
+		}
+
+		reset($this->headers);
+		$this->headerStr = '';
+
+		foreach ($this->headers as $key => $val)
+		{
+			$val = trim($val);
+
+			if ($val !== '')
+			{
+				$this->headerStr .= $key . ': ' . $val . $this->newline;
+			}
+		}
+
+		if ($this->getProtocol() === 'mail')
+		{
+			$this->headerStr = rtrim($this->headerStr);
+		}
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Build Final Body and attachments
+	 */
+	protected function buildMessage()
+	{
+		if ($this->wordWrap === true && $this->mailType !== 'html')
+		{
+			$this->body = $this->wordWrap($this->body);
+		}
+
+		$this->writeHeaders();
+
+		$hdr  = ($this->getProtocol() === 'mail') ? $this->newline : '';
+		$body = '';
+
+		switch ($this->getContentType())
+		{
+			case 'plain':
+
+				$hdr .= 'Content-Type: text/plain; charset=' . $this->charset . $this->newline
+						. 'Content-Transfer-Encoding: ' . $this->getEncoding();
+
+				if ($this->getProtocol() === 'mail')
+				{
+					$this->headerStr .= $hdr;
+					$this->finalBody  = $this->body;
+				}
+				else
+				{
+					$this->finalBody = $hdr . $this->newline . $this->newline . $this->body;
+				}
+
+				return;
+
+			case 'html':
+
+				if ($this->sendMultipart === false)
+				{
+					$hdr .= 'Content-Type: text/html; charset=' . $this->charset . $this->newline
+							. 'Content-Transfer-Encoding: quoted-printable';
+				}
+				else
+				{
+					$boundary = uniqid('B_ALT_', true);
+					$hdr     .= 'Content-Type: multipart/alternative; boundary="' . $boundary . '"';
+
+					$body .= $this->getMimeMessage() . $this->newline . $this->newline
+							. '--' . $boundary . $this->newline
+							. 'Content-Type: text/plain; charset=' . $this->charset . $this->newline
+							. 'Content-Transfer-Encoding: ' . $this->getEncoding() . $this->newline . $this->newline
+							. $this->getAltMessage() . $this->newline . $this->newline
+							. '--' . $boundary . $this->newline
+							. 'Content-Type: text/html; charset=' . $this->charset . $this->newline
+							. 'Content-Transfer-Encoding: quoted-printable' . $this->newline . $this->newline;
+				}
+
+				$this->finalBody = $body . $this->prepQuotedPrintable($this->body) . $this->newline . $this->newline;
+
+				if ($this->getProtocol() === 'mail')
+				{
+					$this->headerStr .= $hdr;
+				}
+				else
+				{
+					$this->finalBody = $hdr . $this->newline . $this->newline . $this->finalBody;
+				}
+
+				if ($this->sendMultipart !== false)
+				{
+					$this->finalBody .= '--' . $boundary . '--';
+				}
+
+				return;
+
+			case 'plain-attach':
+
+				$boundary = uniqid('B_ATC_', true);
+				$hdr     .= 'Content-Type: multipart/mixed; boundary="' . $boundary . '"';
+
+				if ($this->getProtocol() === 'mail')
+				{
+					$this->headerStr .= $hdr;
+				}
+
+				$body .= $this->getMimeMessage() . $this->newline
+						. $this->newline
+						. '--' . $boundary . $this->newline
+						. 'Content-Type: text/plain; charset=' . $this->charset . $this->newline
+						. 'Content-Transfer-Encoding: ' . $this->getEncoding() . $this->newline
+						. $this->newline
+						. $this->body . $this->newline . $this->newline;
+
+				$this->appendAttachments($body, $boundary);
+
+				break;
+			case 'html-attach':
+
+				$alt_boundary  = uniqid('B_ALT_', true);
+				$last_boundary = null;
+
+				if ($this->attachmentsHaveMultipart('mixed'))
+				{
+					$atc_boundary  = uniqid('B_ATC_', true);
+					$hdr          .= 'Content-Type: multipart/mixed; boundary="' . $atc_boundary . '"';
+					$last_boundary = $atc_boundary;
+				}
+
+				if ($this->attachmentsHaveMultipart('related'))
+				{
+					$rel_boundary        = uniqid('B_REL_', true);
+					$rel_boundary_header = 'Content-Type: multipart/related; boundary="' . $rel_boundary . '"';
+
+					if (isset($last_boundary))
+					{
+						$body .= '--' . $last_boundary . $this->newline . $rel_boundary_header;
+					}
+					else
+					{
+						$hdr .= $rel_boundary_header;
+					}
+
+					$last_boundary = $rel_boundary;
+				}
+
+				if ($this->getProtocol() === 'mail')
+				{
+					$this->headerStr .= $hdr;
+				}
+
+				static::strlen($body) && $body .= $this->newline . $this->newline;
+				$body                          .= $this->getMimeMessage() . $this->newline . $this->newline
+						. '--' . $last_boundary . $this->newline
+						. 'Content-Type: multipart/alternative; boundary="' . $alt_boundary . '"' . $this->newline . $this->newline
+						. '--' . $alt_boundary . $this->newline
+						. 'Content-Type: text/plain; charset=' . $this->charset . $this->newline
+						. 'Content-Transfer-Encoding: ' . $this->getEncoding() . $this->newline . $this->newline
+						. $this->getAltMessage() . $this->newline . $this->newline
+						. '--' . $alt_boundary . $this->newline
+						. 'Content-Type: text/html; charset=' . $this->charset . $this->newline
+						. 'Content-Transfer-Encoding: quoted-printable' . $this->newline . $this->newline
+						. $this->prepQuotedPrintable($this->body) . $this->newline . $this->newline
+						. '--' . $alt_boundary . '--' . $this->newline . $this->newline;
+
+				if (! empty($rel_boundary))
+				{
+					$body .= $this->newline . $this->newline;
+					$this->appendAttachments($body, $rel_boundary, 'related');
+				}
+
+				// multipart/mixed attachments
+				if (! empty($atc_boundary))
+				{
+					$body .= $this->newline . $this->newline;
+					$this->appendAttachments($body, $atc_boundary, 'mixed');
+				}
+
+				break;
+		}
+
+		$this->finalBody = ($this->getProtocol() === 'mail') ? $body : $hdr . $this->newline . $this->newline . $body;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Prepares attachment string
+	 *
+	 * @param string      &$body     Message body to append to
+	 * @param string      $boundary  Multipart boundary
+	 * @param string|null $multipart When provided, only attachments of this type will be processed
+	 *
+	 * @return string
+	 */
+	protected function appendAttachments(&$body, $boundary, $multipart = null)
+	{
+		for ($i = 0, $c = count($this->attachments); $i < $c; $i ++)
+		{
+			if (isset($multipart) && $this->attachments[$i]['multipart'] !== $multipart)
+			{
+				continue;
+			}
+
+			$name = isset($this->attachments[$i]['name'][1]) ? $this->attachments[$i]['name'][1] : basename($this->attachments[$i]['name'][0]);
+
+			$body .= '--' . $boundary . $this->newline
+					. 'Content-Type: ' . $this->attachments[$i]['type'] . '; name="' . $name . '"' . $this->newline
+					. 'Content-Disposition: ' . $this->attachments[$i]['disposition'] . ';' . $this->newline
+					. 'Content-Transfer-Encoding: base64' . $this->newline
+					. (empty($this->attachments[$i]['cid']) ? '' : 'Content-ID: <' . $this->attachments[$i]['cid'] . '>' . $this->newline)
+					. $this->newline
+					. $this->attachments[$i]['content'] . $this->newline;
+		}
+
+		// $name won't be set if no attachments were appended,
+		// and therefore a boundary wouldn't be necessary
+		empty($name) || $body .= '--' . $boundary . '--';
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Prep Quoted Printable
+	 *
+	 * Prepares string for Quoted-Printable Content-Transfer-Encoding
+	 * Refer to RFC 2045 http://www.ietf.org/rfc/rfc2045.txt
+	 *
+	 * @param string $str
+	 *
+	 * @return string
+	 */
+	protected function prepQuotedPrintable($str)
+	{
+		// ASCII code numbers for "safe" characters that can always be
+		// used literally, without encoding, as described in RFC 2049.
+		// http://www.ietf.org/rfc/rfc2049.txt
+		static $ascii_safe_chars = [
+			// ' (  )   +   ,   -   .   /   :   =   ?
+			39,
+			40,
+			41,
+			43,
+			44,
+			45,
+			46,
+			47,
+			58,
+			61,
+			63,
+			// numbers
+			48,
+			49,
+			50,
+			51,
+			52,
+			53,
+			54,
+			55,
+			56,
+			57,
+			// upper-case letters
+			65,
+			66,
+			67,
+			68,
+			69,
+			70,
+			71,
+			72,
+			73,
+			74,
+			75,
+			76,
+			77,
+			78,
+			79,
+			80,
+			81,
+			82,
+			83,
+			84,
+			85,
+			86,
+			87,
+			88,
+			89,
+			90,
+			// lower-case letters
+			97,
+			98,
+			99,
+			100,
+			101,
+			102,
+			103,
+			104,
+			105,
+			106,
+			107,
+			108,
+			109,
+			110,
+			111,
+			112,
+			113,
+			114,
+			115,
+			116,
+			117,
+			118,
+			119,
+			120,
+			121,
+			122,
+		];
+
+		// We are intentionally wrapping so mail servers will encode characters
+		// properly and MUAs will behave, so {unwrap} must go!
+		$str = str_replace(['{unwrap}', '{/unwrap}'], '', $str);
+
+		// RFC 2045 specifies CRLF as "\r\n".
+		// However, many developers choose to override that and violate
+		// the RFC rules due to (apparently) a bug in MS Exchange,
+		// which only works with "\n".
+		if ($this->CRLF === "\r\n")
+		{
+			return quoted_printable_encode($str);
+		}
+
+		// Reduce multiple spaces & remove nulls
+		$str = preg_replace(['| +|', '/\x00+/'], [' ', ''], $str);
+
+		// Standardize newlines
+		if (strpos($str, "\r") !== false)
+		{
+			$str = str_replace(["\r\n", "\r"], "\n", $str);
+		}
+
+		$escape = '=';
+		$output = '';
+
+		foreach (explode("\n", $str) as $line)
+		{
+			$length = static::strlen($line);
+			$temp   = '';
+
+			// Loop through each character in the line to add soft-wrap
+			// characters at the end of a line " =\r\n" and add the newly
+			// processed line(s) to the output (see comment on $crlf class property)
+			for ($i = 0; $i < $length; $i ++)
+			{
+				// Grab the next character
+				$char  = $line[$i];
+				$ascii = ord($char);
+
+				// Convert spaces and tabs but only if it's the end of the line
+				if ($ascii === 32 || $ascii === 9)
+				{
+					if ($i === ($length - 1))
+					{
+						$char = $escape . sprintf('%02s', dechex($ascii));
+					}
+				}
+				// DO NOT move this below the $ascii_safe_chars line!
+				//
+				// = (equals) signs are allowed by RFC2049, but must be encoded
+				// as they are the encoding delimiter!
+				elseif ($ascii === 61)
+				{
+					$char = $escape . strtoupper(sprintf('%02s', dechex($ascii)));  // =3D
+				}
+				elseif (! in_array($ascii, $ascii_safe_chars, true))
+				{
+					$char = $escape . strtoupper(sprintf('%02s', dechex($ascii)));
+				}
+
+				// If we're at the character limit, add the line to the output,
+				// reset our temp variable, and keep on chuggin'
+				if ((static::strlen($temp) + static::strlen($char)) >= 76)
+				{
+					$output .= $temp . $escape . $this->CRLF;
+					$temp    = '';
+				}
+
+				// Add the character to our temporary line
+				$temp .= $char;
+			}
+
+			// Add our completed line to the output
+			$output .= $temp . $this->CRLF;
+		}
+
+		// get rid of extra CRLF tacked onto the end
+		return static::substr($output, 0, static::strlen($this->CRLF) * -1);
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Prep Q Encoding
+	 *
+	 * Performs "Q Encoding" on a string for use in email headers.
+	 * It's related but not identical to quoted-printable, so it has its
+	 * own method.
+	 *
+	 * @param string $str
+	 *
+	 * @return string
+	 */
+	protected function prepQEncoding($str)
+	{
+		$str = str_replace(["\r", "\n"], '', $str);
+
+		if ($this->charset === 'UTF-8')
+		{
+			// Note: We used to have mb_encode_mimeheader() as the first choice
+			//       here, but it turned out to be buggy and unreliable. DO NOT
+			//       re-add it! -- Narf
+			if (extension_loaded('iconv'))
+			{
+				$output = @iconv_mime_encode(
+								'', $str, [
+									'scheme'           => 'Q',
+									'line-length'      => 76,
+									'input-charset'    => $this->charset,
+									'output-charset'   => $this->charset,
+									'line-break-chars' => $this->CRLF,
+								]);
+
+				// There are reports that iconv_mime_encode() might fail and return FALSE
+				if ($output !== false)
+				{
+					// iconv_mime_encode() will always put a header field name.
+					// We've passed it an empty one, but it still prepends our
+					// encoded string with ': ', so we need to strip it.
+					return static::substr($output, 2);
+				}
+
+				$chars = iconv_strlen($str, 'UTF-8');
+			}
+			elseif (extension_loaded('mbstring'))
+			{
+				$chars = mb_strlen($str, 'UTF-8');
+			}
+		}
+
+		// We might already have this set for UTF-8
+		isset($chars) || $chars = static::strlen($str);
+
+		$output = '=?' . $this->charset . '?Q?';
+		for ($i = 0, $length = static::strlen($output); $i < $chars; $i ++)
+		{
+			$chr = ($this->charset === 'UTF-8' && ICONV_ENABLED === true) ? '=' . implode('=', str_split(strtoupper(bin2hex(iconv_substr($str, $i, 1, $this->charset))), 2)) : '=' . strtoupper(bin2hex($str[$i]));
+
+			// RFC 2045 sets a limit of 76 characters per line.
+			// We'll append ?= to the end of each line though.
+			if ($length + ($l = static::strlen($chr)) > 74)
+			{
+				$output .= '?=' . $this->CRLF // EOL
+						. ' =?' . $this->charset . '?Q?' . $chr; // New line
+				$length  = 6 + static::strlen($this->charset) + $l; // Reset the length for the new line
+			}
+			else
+			{
+				$output .= $chr;
+				$length += $l;
+			}
+		}
+
+		// End the header
+		return $output . '?=';
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Send a Message
+	 *
+	 * @param boolean $autoClear
+	 *
+	 * @return boolean
+	 */
+	public function send(Message $message, bool $autoClear = true, bool $reallySend = true)
+	{
+		if (! isset($this->headers['From']) && ! empty($this->fromEmail))
+		{
+			$this->setFrom($this->fromEmail, $this->fromName);
+		}
+
+		if (! isset($this->headers['From']))
+		{
+			throw MailerException::forNoFrom();
+		}
+
+		if ($this->replyToFlag === false)
+		{
+			$this->setReplyTo($this->headers['From']);
+		}
+
+		if (empty($this->recipients) && ! isset($this->headers['To']) && empty($this->BCCArray) && ! isset($this->headers['Bcc']) && ! isset($this->headers['Cc'])
+		)
+		{
+			throw MailerException::forNoRecipients();
+		}
+
+		$this->buildHeaders();
+
+		if ($this->BCCBatchMode && count($this->BCCArray) > $this->BCCBatchSize)
+		{
+			$this->batchBCCSend();
+
+			if ($autoClear)
+			{
+				$this->clear();
+			}
+
+			return true;
+		}
+
+		$this->buildMessage();
+		$result = $this->spoolEmail();
+
+		if ($result && $autoClear)
+		{
+			$this->clear();
+		}
+
+		return $result;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Batch Bcc Send. Sends groups of BCCs in batches
+	 */
+	public function batchBCCSend()
+	{
+		$float = $this->BCCBatchSize - 1;
+		$set   = '';
+		$chunk = [];
+
+		for ($i = 0, $c = count($this->BCCArray); $i < $c; $i ++)
+		{
+			if (isset($this->BCCArray[$i]))
+			{
+				$set .= ', ' . $this->BCCArray[$i];
+			}
+
+			if ($i === $float)
+			{
+				$chunk[] = static::substr($set, 1);
+				$float  += $this->BCCBatchSize;
+				$set     = '';
+			}
+
+			if ($i === $c - 1)
+			{
+				$chunk[] = static::substr($set, 1);
+			}
+		}
+
+		for ($i = 0, $c = count($chunk); $i < $c; $i ++)
+		{
+			unset($this->headers['Bcc']);
+
+			$bcc = $this->cleanEmail($this->stringToArray($chunk[$i]));
+
+			if ($this->protocol !== 'smtp')
+			{
+				$this->setHeader('Bcc', implode(', ', $bcc));
+			}
+			else
+			{
+				$this->BCCArray = $bcc;
+			}
+
+			$this->buildMessage();
+			$this->spoolEmail();
+		}
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Unwrap special elements
+	 */
+	protected function unwrapSpecials()
+	{
+		$this->finalBody = preg_replace_callback(
+				'/\{unwrap\}(.*?)\{\/unwrap\}/si', [
+					$this,
+					'removeNLCallback',
+				], $this->finalBody
+		);
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Strip line-breaks via callback
+	 *
+	 * @param string $matches
+	 *
+	 * @return string
+	 */
+	protected function removeNLCallback($matches)
+	{
+		if (strpos($matches[1], "\r") !== false || strpos($matches[1], "\n") !== false)
+		{
+			$matches[1] = str_replace(["\r\n", "\r", "\n"], '', $matches[1]);
+		}
+
+		return $matches[1];
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Spool mail to the mail server
+	 *
+	 * @return boolean
+	 */
+	protected function spoolEmail()
+	{
+		$this->unwrapSpecials();
+
+		$protocol = $this->getProtocol();
+		$method   = 'sendWith' . ucfirst($protocol);
+		try
+		{
+			$success = $this->$method();
+		}
+		catch (\ErrorException $e)
+		{
+			$success = false;
+			$this->logger->error('Mailer: ' . $method . ' throwed ' . $e->getMessage());
+		}
+
+		if (! $success)
+		{
+			throw MailerException::forSendFailure($protocol === 'mail' ? 'PHPMail' : ucfirst($protocol));
+		}
+
+		$this->setErrorMessage(lang('Mailer.sent', [$protocol]));
+
+		return true;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Validate email for shell
+	 *
+	 * Applies stricter, shell-safe validation to email addresses.
+	 * Introduced to prevent RCE via sendmail's -f option.
+	 *
+	 * @see     https://github.com/codeigniter4/CodeIgniter/issues/4963
+	 * @see     https://gist.github.com/Zenexer/40d02da5e07f151adeaeeaa11af9ab36
+	 * @license https://creativecommons.org/publicdomain/zero/1.0/    CC0 1.0, Public Domain
+	 *
+	 * Credits for the base concept go to Paul Buonopane <paul@namepros.com>
+	 *
+	 * @param string &$email
+	 *
+	 * @return boolean
+	 */
+	protected function validateEmailForShell(&$email)
+	{
+		if (function_exists('idn_to_ascii') && $atpos = strpos($email, '@'))
+		{
+			$email = static::substr($email, 0, ++ $atpos) . idn_to_ascii(
+							static::substr($email, $atpos), 0, INTL_IDNA_VARIANT_UTS46
+			);
+		}
+
+		return (filter_var($email, FILTER_VALIDATE_EMAIL) === $email && preg_match('#\A[a-z0-9._+-]+@[a-z0-9.-]{1,253}\z#i', $email));
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Send using mail()
+	 *
+	 * @return boolean
+	 */
+	protected function sendWithMail()
+	{
+		if (is_array($this->recipients))
+		{
+			$this->recipients = implode(', ', $this->recipients);
+		}
+
+		// _validate_email_for_shell() below accepts by reference,
+		// so this needs to be assigned to a variable
+		$from = $this->cleanEmail($this->headers['Return-Path']);
+
+		if (! $this->validateEmailForShell($from))
+		{
+			return mail($this->recipients, $this->subject, $this->finalBody, $this->headerStr);
+		}
+
+		// most documentation of sendmail using the "-f" flag lacks a space after it, however
+		// we've encountered servers that seem to require it to be in place.
+		return mail($this->recipients, $this->subject, $this->finalBody, $this->headerStr, '-f ' . $from);
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Send using Sendmail
+	 *
+	 * @return boolean
+	 */
+	protected function sendWithSendmail()
+	{
+		// _validate_email_for_shell() below accepts by reference,
+		// so this needs to be assigned to a variable
+		$from = $this->cleanEmail($this->headers['From']);
+		if ($this->validateEmailForShell($from))
+		{
+			$from = '-f ' . $from;
+		}
+		else
+		{
+			$from = '';
+		}
+
+		// is popen() enabled?
+		if (! function_usable('popen') || false === ($fp = @popen($this->mailPath . ' -oi ' . $from . ' -t', 'w')))
+		{
+			// server probably has popen disabled, so nothing we can do to get a verbose error.
+			return false;
+		}
+
+		fputs($fp, $this->headerStr);
+		fputs($fp, $this->finalBody);
+
+		$status = pclose($fp);
+
+		if ($status !== 0)
+		{
+			throw MailerException::forNosocket($status);
+		}
+
+		return true;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Send using SMTP
+	 *
+	 * @return boolean
+	 */
+	protected function sendWithSmtp()
+	{
+		if ($this->SMTPHost === '')
+		{
+			throw MailerException::forNoHostname();
+		}
+
+		if (! $this->SMTPConnect() || ! $this->SMTPAuthenticate())
+		{
+			return false;
+		}
+
+		if (! $this->sendCommand('from', $this->cleanEmail($this->headers['From'])))
+		{
+			$this->SMTPEnd();
+
+			return false;
+		}
+
+		foreach ($this->recipients as $val)
+		{
+			if (! $this->sendCommand('to', $val))
+			{
+				$this->SMTPEnd();
+
+				return false;
+			}
+		}
+
+		foreach ($this->CCArray as $val)
+		{
+			if ($val !== '' && ! $this->sendCommand('to', $val))
+			{
+				$this->SMTPEnd();
+
+				return false;
+			}
+		}
+
+		foreach ($this->BCCArray as $val)
+		{
+			if ($val !== '' && ! $this->sendCommand('to', $val))
+			{
+				$this->SMTPEnd();
+
+				return false;
+			}
+		}
+
+		if (! $this->sendCommand('data'))
+		{
+			$this->SMTPEnd();
+
+			return false;
+		}
+
+		// perform dot transformation on any lines that begin with a dot
+		$this->sendData($this->headerStr . preg_replace('/^\./m', '..$1', $this->finalBody));
+
+		$this->sendData('.');
+		$reply = $this->getSMTPData();
+		$this->setErrorMessage($reply);
+
+		$this->SMTPEnd();
+
+		if (strpos($reply, '250') !== 0)
+		{
+			throw MailerException::forSMTPError($reply);
+		}
+
+		return true;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * SMTP End
+	 *
+	 * Shortcut to send RSET or QUIT depending on keep-alive
+	 */
+	protected function SMTPEnd()
+	{
+		$this->sendCommand($this->SMTPKeepAlive ? 'reset' : 'quit');
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * SMTP Connect
+	 *
+	 * @return string
+	 */
+	protected function SMTPConnect()
+	{
+		if (is_resource($this->SMTPConnect))
+		{
+			return true;
+		}
+
+		$ssl = ($this->SMTPCrypto === 'ssl') ? 'ssl://' : '';
+
+		$this->SMTPConnect = fsockopen(
+				$ssl . $this->SMTPHost, $this->SMTPPort, $errno, $errstr, $this->SMTPTimeout
+		);
+
+		if (! is_resource($this->SMTPConnect))
+		{
+			throw MailerException::forSMTPError($errno . ' ' . $errstr);
+		}
+
+		stream_set_timeout($this->SMTPConnect, $this->SMTPTimeout);
+		$this->setErrorMessage($this->getSMTPData());
+
+		if ($this->SMTPCrypto === 'tls')
+		{
+			$this->sendCommand('hello');
+			$this->sendCommand('starttls');
+
+			$crypto = stream_socket_enable_crypto($this->SMTPConnect, true, STREAM_CRYPTO_METHOD_TLS_CLIENT);
+
+			if ($crypto !== true)
+			{
+				throw MailerException::forSMTPError($this->getSMTPData());
+			}
+		}
+
+		return $this->sendCommand('hello');
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Send SMTP command
+	 *
+	 * @param string $cmd
+	 * @param string $data
+	 *
+	 * @return boolean
+	 */
+	protected function sendCommand($cmd, $data = '')
+	{
+		switch ($cmd)
+		{
+			case 'hello':
+				if ($this->SMTPAuth || $this->getEncoding() === '8bit')
+				{
+					$this->sendData('EHLO ' . $this->getHostname());
+				}
+				else
+				{
+					$this->sendData('HELO ' . $this->getHostname());
+				}
+
+				$resp = 250;
+				break;
+			case 'starttls':
+				$this->sendData('STARTTLS');
+				$resp = 220;
+				break;
+			case 'from':
+				$this->sendData('MAIL FROM:<' . $data . '>');
+				$resp = 250;
+				break;
+			case 'to':
+				if ($this->DSN)
+				{
+					$this->sendData('RCPT TO:<' . $data . '> NOTIFY=SUCCESS,DELAY,FAILURE ORCPT=rfc822;' . $data);
+				}
+				else
+				{
+					$this->sendData('RCPT TO:<' . $data . '>');
+				}
+				$resp = 250;
+				break;
+			case 'data':
+				$this->sendData('DATA');
+				$resp = 354;
+				break;
+			case 'reset':
+				$this->sendData('RSET');
+				$resp = 250;
+				break;
+			case 'quit':
+				$this->sendData('QUIT');
+				$resp = 221;
+				break;
+		}
+
+		$reply = $this->getSMTPData();
+
+		$this->debugMessage[] = '<pre>' . $cmd . ': ' . $reply . '</pre>';
+
+		if ((int) static::substr($reply, 0, 3) !== $resp)
+		{
+			throw MailerException::forSMTPError($reply);
+		}
+
+		if ($cmd === 'quit')
+		{
+			fclose($this->SMTPConnect);
+		}
+
+		return true;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * SMTP Authenticate
+	 *
+	 * @return boolean
+	 */
+	protected function SMTPAuthenticate()
+	{
+		if (! $this->SMTPAuth)
+		{
+			return true;
+		}
+
+		if ($this->SMTPUser === '' && $this->SMTPPass === '')
+		{
+			throw MailerException::forNoSMTPAuth();
+		}
+
+		$this->sendData('AUTH LOGIN');
+		$reply = $this->getSMTPData();
+
+		if (strpos($reply, '503') === 0)    // Already authenticated
+		{
+			return true;
+		}
+		elseif (strpos($reply, '334') !== 0)
+		{
+			throw MailerException::forFailedSMTPLogin($reply);
+		}
+
+		$this->sendData(base64_encode($this->SMTPUser));
+		$reply = $this->getSMTPData();
+
+		if (strpos($reply, '334') !== 0)
+		{
+			throw MailerException::forSMTPAuthUsername($reply);
+		}
+
+		$this->sendData(base64_encode($this->SMTPPass));
+		$reply = $this->getSMTPData();
+
+		if (strpos($reply, '235') !== 0)
+		{
+			throw MailerException::forSMTPAuthPassword($reply);
+		}
+
+		if ($this->SMTPKeepAlive)
+		{
+			$this->SMTPAuth = false;
+		}
+
+		return true;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Send SMTP data
+	 *
+	 * @param string $data
+	 *
+	 * @return boolean
+	 */
+	protected function sendData($data)
+	{
+		$data .= $this->newline;
+		for ($written = $timestamp = 0, $length = static::strlen($data); $written < $length; $written += $result)
+		{
+			if (($result = fwrite($this->SMTPConnect, static::substr($data, $written))) === false)
+			{
+				break;
+			}
+			// See https://bugs.php.net/bug.php?id=39598 and http://php.net/manual/en/function.fwrite.php#96951
+			elseif ($result === 0)
+			{
+				if ($timestamp === 0)
+				{
+					$timestamp = time();
+				}
+				elseif ($timestamp < (time() - $this->SMTPTimeout))
+				{
+					$result = false;
+					break;
+				}
+
+				usleep(250000);
+				continue;
+			}
+			else
+			{
+				$timestamp = 0;
+			}
+		}
+
+		if ($result === false)
+		{
+			throw MailerException::forSMTPDataFailure($data);
+		}
+
+		return true;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Get SMTP data
+	 *
+	 * @return string
+	 */
+	protected function getSMTPData()
+	{
+		$data = '';
+
+		while ($str = fgets($this->SMTPConnect, 512))
+		{
+			$data .= $str;
+
+			if ($str[3] === ' ')
+			{
+				break;
+			}
+		}
+
+		return $data;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Get Hostname
+	 *
+	 * There are only two legal types of hostname - either a fully
+	 * qualified domain name (eg: "mail.example.com") or an IP literal
+	 * (eg: "[1.2.3.4]").
+	 *
+	 * @link https://tools.ietf.org/html/rfc5321#section-2.3.5
+	 * @link http://cbl.abuseat.org/namingproblems.html
+	 *
+	 * @return string
+	 */
+	protected function getHostname()
+	{
+		if (isset($_SERVER['SERVER_NAME']))
+		{
+			return $_SERVER['SERVER_NAME'];
+		}
+
+		return isset($_SERVER['SERVER_ADDR']) ? '[' . $_SERVER['SERVER_ADDR'] . ']' : '[127.0.0.1]';
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Get Debug Message
+	 *
+	 * @param array $include List of raw data chunks to include in the output
+	 *                       Valid options are: 'headers', 'subject', 'body'
+	 *
+	 * @return string
+	 */
+	public function printDebugger($include = ['headers', 'subject', 'body'])
+	{
+		$msg = implode('', $this->debugMessage);
+
+		// Determine which parts of our raw data needs to be printed
+		$raw_data                      = '';
+		is_array($include) || $include = [$include];
+
+		in_array('headers', $include, true) && $raw_data  = htmlspecialchars($this->headerStr) . "\n";
+		in_array('subject', $include, true) && $raw_data .= htmlspecialchars($this->subject) . "\n";
+		in_array('body', $include, true) && $raw_data    .= htmlspecialchars($this->finalBody);
+
+		return $msg . ($raw_data === '' ? '' : '<pre>' . $raw_data . '</pre>');
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Set Message
+	 *
+	 * @param string $msg
+	 */
+	protected function setErrorMessage($msg)
+	{
+		$this->debugMessage[] = $msg . '<br />';
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Mime Types
+	 *
+	 * @param string $ext
+	 *
+	 * @return string
+	 */
+	protected function mimeTypes($ext = '')
+	{
+		$mime = Mimes::guessTypeFromExtension(strtolower($ext));
+
+		return ! empty($mime) ? $mime : 'application/x-unknown-content-type';
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Destructor
+	 */
+	public function __destruct()
+	{
+		is_resource($this->SMTPConnect) && $this->sendCommand('quit');
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Byte-safe strlen()
+	 *
+	 * @param string $str
+	 *
+	 * @return integer
+	 */
+	protected static function strlen($str)
+	{
+		return (static::$func_overload) ? mb_strlen($str, '8bit') : strlen($str);
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Byte-safe substr()
+	 *
+	 * @param string       $str
+	 * @param integer      $start
+	 * @param integer|null $length
+	 *
+	 * @return string
+	 */
+	protected static function substr($str, $start, $length = null)
+	{
+		if (static::$func_overload)
+		{
+			return mb_substr($str, $start, $length, '8bit');
+		}
+
+		return isset($length) ? substr($str, $start, $length) : substr($str, $start);
+	}
+
+}
diff --git a/system/Mailer/MailerInterface.php b/system/Mailer/MailerInterface.php
new file mode 100644
index 000000000000..d05e21508407
--- /dev/null
+++ b/system/Mailer/MailerInterface.php
@@ -0,0 +1,59 @@
+<?php namespace CodeIgniter\Mailer;
+
+/**
+ * CodeIgniter
+ *
+ * An open source application development framework for PHP
+ *
+ * This content is released under the MIT License (MIT)
+ *
+ * Copyright (c) 2014-2018 British Columbia Institute of Technology
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ * @package    CodeIgniter
+ * @author     CodeIgniter Dev Team
+ * @copyright  2014-2018 British Columbia Institute of Technology (https://bcit.ca/)
+ * @license    https://opensource.org/licenses/MIT	MIT License
+ * @link       https://codeigniter.com
+ * @since      Version 3.0.0
+ * @filesource
+ */
+
+/**
+ * Expected behavior of a Mailer handler used with CodeIgniter.
+ */
+interface MailerInterface
+{
+	/**
+	 * Send a Message
+	 *
+	 * @param Message $message    The email to send
+	 * @param boolean $autoClear  Should old session data be destroyed?
+	 * @param boolean $reallySend Should the message really be sent? or everything but that
+	 */
+	public function send(Message $message, bool $autoClear = true, bool $reallySend = true);
+
+	/**
+	 * Which protocol is this a handler for?
+	 */
+	public function getProtocol(): string;
+
+	//--------------------------------------------------------------------
+}
diff --git a/system/Mailer/Message.php b/system/Mailer/Message.php
new file mode 100644
index 000000000000..a29cd47181bf
--- /dev/null
+++ b/system/Mailer/Message.php
@@ -0,0 +1,1220 @@
+<?php namespace CodeIgniter\Mailer;
+
+/**
+ * CodeIgniter
+ *
+ * An open source application development framework for PHP
+ *
+ * This content is released under the MIT License (MIT)
+ *
+ * Copyright (c) 2014 - 2019, British Columbia Institute of Technology
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ * @package    CodeIgniter
+ * @author     EllisLab Dev Team
+ * @copyright  Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
+ * @copyright  Copyright (c) 2014 - 2020, British Columbia Institute of Technology (http://bcit.ca/)
+ * @license    http://opensource.org/licenses/MIT    MIT License
+ * @link       https://codeigniter.com
+ * @since      Version 1.0.0
+ * @filesource
+ */
+
+use CodeIgniter\Config\Services;
+use CodeIgniter\Mailer\Exceptions\MailerException;
+use Config\Mailer as MailerConfig;
+use Config\Mimes;
+use Psr\Log\LoggerAwareTrait;
+
+/**
+ * CodeIgniter Message Class
+ *
+ * Object model for a message to be sent using Mail, Sendmail, or SMTP.
+ */
+class Message
+{
+	use LoggerAwareTrait;
+
+	/**
+	 * @var string
+	 */
+	public $fromEmail;
+
+	/**
+	 * @var string
+	 */
+	public $fromName;
+
+	/**
+	 * Whether to apply word-wrapping to the message body.
+	 *
+	 * @var boolean
+	 */
+	public $wordWrap = true;
+
+	/**
+	 * Number of characters to wrap at.
+	 *
+	 * @see self::$wordWrap
+	 * @var integer
+	 */
+	public $wrapChars = 76;
+
+	/**
+	 * Message format.
+	 *
+	 * @var string 'text' or 'html'
+	 */
+	public $mailType = 'text';
+
+	/**
+	 * Character set (default: utf-8)
+	 *
+	 * @var string
+	 */
+	public $charset = 'utf-8';
+
+	/**
+	 * Alternative message (for HTML messages only)
+	 *
+	 * @var string
+	 */
+	public $altMessage = '';
+
+	/**
+	 * Whether to validate e-mail addresses.
+	 *
+	 * @var boolean
+	 */
+	public $validate = true;
+
+	/**
+	 * X-Priority header value.
+	 *
+	 * @var integer 1-5
+	 */
+	public $priority = 3;   // Default priority (1 - 5)
+
+	/**
+	 * Newline character sequence.
+	 * Use "\r\n" to comply with RFC 822.
+	 *
+	 * @link http://www.ietf.org/rfc/rfc822.txt
+	 * @var  string "\r\n" or "\n"
+	 */
+	public $newline = "\n";   // Default newline. "\r\n" or "\n" (Use "\r\n" to comply with RFC 822)
+
+	/**
+	 * CRLF character sequence
+	 *
+	 * RFC 2045 specifies that for 'quoted-printable' encoding,
+	 * "\r\n" must be used. However, it appears that some servers
+	 * (even on the receiving end) don't handle it properly and
+	 * switching to "\n", while improper, is the only solution
+	 * that seems to work for all environments.
+	 *
+	 * @link http://www.ietf.org/rfc/rfc822.txt
+	 * @var  string
+	 */
+	public $CRLF = "\n";
+
+	/**
+	 * Whether to use Delivery Status Notification.
+	 *
+	 * @var boolean
+	 */
+	public $DSN = false;
+
+	/**
+	 * Whether to send multipart alternatives.
+	 * Yahoo! doesn't seem to like these.
+	 *
+	 * @var boolean
+	 */
+	public $sendMultipart = true;
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Subject header
+	 *
+	 * @var string
+	 */
+	protected $subject = '';
+
+	/**
+	 * Message body
+	 *
+	 * @var string
+	 */
+	protected $body = '';
+
+	/**
+	 * Final message body to be sent.
+	 *
+	 * @var string
+	 */
+	protected $finalBody = '';
+
+	/**
+	 * Final headers to send
+	 *
+	 * @var string
+	 */
+	protected $headerStr = '';
+
+	/**
+	 * Mail encoding
+	 *
+	 * @var string '8bit' or '7bit'
+	 */
+	protected $encoding = '8bit';
+
+	/**
+	 * Whether to send a Reply-To header
+	 *
+	 * @var boolean
+	 */
+	protected $replyToFlag = false;
+
+	/**
+	 * Debug messages
+	 *
+	 * @see self::printDebugger()
+	 * @var array
+	 */
+	protected $debugMessage = [];
+
+	/**
+	 * Recipients
+	 *
+	 * @var array
+	 */
+	protected $recipients = [];
+
+	/**
+	 * CC Recipients
+	 *
+	 * @var array
+	 */
+	protected $CCArray = [];
+
+	/**
+	 * BCC Recipients
+	 *
+	 * @var array
+	 */
+	protected $BCCArray = [];
+
+	/**
+	 * Message headers
+	 *
+	 * @var array
+	 */
+	protected $headers = [];
+
+	/**
+	 * Attachment data
+	 *
+	 * @var array
+	 */
+	protected $attachments = [];
+
+	/**
+	 * Which protocol are we using?
+	 *
+	 * @var string
+	 */
+	protected $protocol = 'mail';
+
+	/**
+	 * Valid $protocol values
+	 *
+	 * @see self::$protocol
+	 * @var array
+	 */
+	protected $protocols = [
+		'mail',
+		'sendmail',
+		'smtp',
+	];
+
+	/**
+	 * Base charsets
+	 *
+	 * Character sets valid for 7-bit encoding,
+	 * excluding language suffix.
+	 *
+	 * @var array
+	 */
+	protected $baseCharsets = [
+		'us-ascii',
+		'iso-2022-',
+	];
+
+	/**
+	 * Bit depths
+	 *
+	 * Valid mail encodings
+	 *
+	 * @see self::$encoding
+	 * @var array
+	 */
+	protected $bitDepths = [
+		'7bit',
+		'8bit',
+	];
+
+	/**
+	 * $priority translations
+	 *
+	 * Actual values to send with the X-Priority header
+	 *
+	 * @var array
+	 */
+	protected $priorities = [
+		1 => '1 (Highest)',
+		2 => '2 (High)',
+		3 => '3 (Normal)',
+		4 => '4 (Low)',
+		5 => '5 (Lowest)',
+	];
+
+	/**
+	 * Logger instance to record error messages and awarnings.
+	 *
+	 * @var \Psr\Log\LoggerInterface
+	 */
+	protected $logger;
+
+	/**
+	 * Mailer that this message is bound to
+	 *
+	 * @var \CodeIgniter\Mailer\MailerInterface
+	 */
+	protected $handler;
+
+	/**
+	 * Config settings, used if protocol changed.
+	 *
+	 * @var MailerConfig
+	 */
+	protected $config = null;
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Constructor - Sets Preferences
+	 *
+	 * The constructor can be passed an array of config values
+	 *
+	 * @param array|null $config
+	 */
+	public function __construct($config = null)
+	{
+		if ($config === null)
+		{
+			$config       = new \Config\Mailer();
+			$this->config = $config;
+		}
+		else if (is_array($config))
+		{
+			$mergedConfig = new \Config\Mailer();
+			foreach ($config as $key => $value)
+			{
+				$mergedConfig->$key = $value;
+			}
+			$this->config = $mergedConfig;
+		}
+		$this->initialize($config);
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Initialize preferences
+	 *
+	 * @param array|\Config\Mailer $config
+	 *
+	 * @return $this
+	 */
+	public function initialize($config)
+	{
+		$this->clear();
+		if ($config instanceof \Config\Mailer)
+		{
+			$config = get_object_vars($config);
+		}
+
+		foreach (get_class_vars(get_class($this)) as $key => $value)
+		{
+			if (property_exists($this, $key) && isset($config[$key]))
+			{
+				$method = 'set' . ucfirst($key);
+
+				if (method_exists($this, $method))
+				{
+					$this->$method($config[$key]);
+				}
+				else
+				{
+					$this->$key = $config[$key];
+				}
+			}
+		}
+
+		$this->charset = strtoupper($this->charset);
+		$this->handler = Services::mailer($config);
+
+		return $this;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Set the protocol to use.
+	 * If valid, get an appropriate handler for it.
+	 *
+	 * @param string $protocol
+	 *
+	 * @returns $this
+	 */
+	public function setProtocol(string $protocol = 'mail')
+	{
+		if (! in_array($protocol, $this->protocols))
+		{
+			throw MailerException::forInvalidProtocol($protocol);
+		}
+
+		$this->protocol         = $protocol;
+		$this->config->protocol = $protocol; // update config too
+		$this->handler          = Services::mailer($this->config, false);
+
+		return $this;
+	}
+
+	/**
+	 * Get the protocol our handler is using.
+	 * Note: the protocol property here is only the requested one.
+	 *
+	 * @return string
+	 */
+	public function getProtocol(): string
+	{
+		return $this->handler->getProtocol();
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Initialize the Data
+	 *
+	 * @param boolean $clearAttachments
+	 *
+	 * @return $this
+	 */
+	public function clear($clearAttachments = false)
+	{
+		$this->subject     = '';
+		$this->body        = '';
+		$this->finalBody   = '';
+		$this->headerStr   = '';
+		$this->replyToFlag = false;
+		$this->recipients  = [];
+		$this->CCArray     = [];
+		$this->BCCArray    = [];
+		$this->headers     = [];
+
+		$this->setHeader('Date', $this->setDate());
+
+		if ($clearAttachments !== false)
+		{
+			$this->attachments = [];
+		}
+
+		return $this;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Set FROM
+	 *
+	 * @param string      $from
+	 * @param string      $name
+	 * @param string|null $returnPath Return-Path
+	 *
+	 * @return $this
+	 */
+	public function setFrom($from, $name = '', $returnPath = null)
+	{
+		if (preg_match('/\<(.*)\>/', $from, $match))
+		{
+			$from = $match[1];
+		}
+
+		if ($this->validate)
+		{
+			$this->validateEmail($from);
+			if ($returnPath)
+			{
+				$this->validateEmail($returnPath);
+			}
+		}
+
+		// prepare the display name
+		if ($name !== '')
+		{
+			// only use Q encoding if there are characters that would require it
+			if (! preg_match('/[\200-\377]/', $name))
+			{
+				// add slashes for non-printing characters, slashes, and double quotes, and surround it in double quotes
+				$name = '"' . addcslashes($name, "\0..\37\177'\"\\") . '"';
+			}
+			else
+			{
+				$name = $this->prepQEncoding($name);
+			}
+		}
+
+		$this->setHeader('From', $name . ' <' . $from . '>');
+		isset($returnPath) || $returnPath = $from;
+		$this->setHeader('Return-Path', '<' . $returnPath . '>');
+
+		return $this;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Prep Q Encoding
+	 *
+	 * Performs "Q Encoding" on a string for use in headers.
+	 * It's related but not identical to quoted-printable, so it has its
+	 * own method.
+	 *
+	 * @param string $str
+	 *
+	 * @return string
+	 */
+	protected function prepQEncoding($str)
+	{
+		$str = str_replace(["\r", "\n"], '', $str);
+
+		if ($this->charset === 'UTF-8')
+		{
+			// Note: We used to have mb_encode_mimeheader() as the first choice
+			//       here, but it turned out to be buggy and unreliable. DO NOT
+			//       re-add it! -- Narf
+			if (extension_loaded('iconv'))
+			{
+				$output = @iconv_mime_encode(
+								'', $str, [
+									'scheme'           => 'Q',
+									'line-length'      => 76,
+									'input-charset'    => $this->charset,
+									'output-charset'   => $this->charset,
+									'line-break-chars' => $this->CRLF,
+								]);
+
+				// There are reports that iconv_mime_encode() might fail and return FALSE
+				if ($output !== false)
+				{
+					// iconv_mime_encode() will always put a header field name.
+					// We've passed it an empty one, but it still prepends our
+					// encoded string with ': ', so we need to strip it.
+					return mb_substr($output, 2);
+				}
+
+				$chars = iconv_strlen($str, 'UTF-8');
+			}
+			elseif (extension_loaded('mbstring'))
+			{
+				$chars = mb_strlen($str, 'UTF-8');
+			}
+		}
+
+		// We might already have this set for UTF-8
+		isset($chars) || $chars = mb_strlen($str);
+
+		$output = '=?' . $this->charset . '?Q?';
+		for ($i = 0, $length = mb_strlen($output); $i < $chars; $i ++)
+		{
+			$chr = ($this->charset === 'UTF-8' && ICONV_ENABLED === true) ? '=' . implode('=', str_split(strtoupper(bin2hex(iconv_substr($str, $i, 1, $this->charset))), 2)) : '=' . strtoupper(bin2hex($str[$i]));
+
+			// RFC 2045 sets a limit of 76 characters per line.
+			// We'll append ?= to the end of each line though.
+			if ($length + ($l = mb_strlen($chr)) > 74)
+			{
+				$output .= '?=' . $this->CRLF // EOL
+						. ' =?' . $this->charset . '?Q?' . $chr; // New line
+				$length  = 6 + mb_strlen($this->charset) + $l; // Reset the length for the new line
+			}
+			else
+			{
+				$output .= $chr;
+				$length += $l;
+			}
+		}
+
+		// End the header
+		return $output . '?=';
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Set Reply-to
+	 *
+	 * @param string $replyto
+	 * @param string $name
+	 *
+	 * @return $this
+	 */
+	public function setReplyTo($replyto, $name = '')
+	{
+		if (preg_match('/\<(.*)\>/', $replyto, $match))
+		{
+			$replyto = $match[1];
+		}
+
+		if ($this->validate)
+		{
+			$this->validateEmail($this->stringToArray($replyto));
+		}
+
+		if ($name !== '')
+		{
+			// only use Q encoding if there are characters that would require it
+			if (! preg_match('/[\200-\377]/', $name))
+			{
+				// add slashes for non-printing characters, slashes, and double quotes, and surround it in double quotes
+				$name = '"' . addcslashes($name, "\0..\37\177'\"\\") . '"';
+			}
+			else
+			{
+				$name = $this->prepQEncoding($name);
+			}
+		}
+
+		$this->setHeader('Reply-To', $name . ' <' . $replyto . '>');
+		$this->replyToFlag = true;
+
+		return $this;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Set Recipients
+	 *
+	 * @param string|array $to One or more recipients
+	 *
+	 * @return $this
+	 */
+	public function setTo($to)
+	{
+		$to = $this->stringToArray($to);
+		$to = $this->cleanEmail($to);
+
+		if ($this->validate)
+		{
+			$this->validateEmail($to);
+		}
+
+		if ($this->handler->getProtocol() !== 'mail')
+		{
+			$this->setHeader('To', implode(', ', $to));
+		}
+
+		$this->recipients = $to;
+
+		return $this;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Set CC
+	 *
+	 * @param string|array $cc
+	 *
+	 * @return $this
+	 */
+	public function setCC($cc)
+	{
+		$cc = $this->cleanEmail($this->stringToArray($cc));
+
+		if ($this->validate)
+		{
+			$this->validateEmail($cc);
+		}
+
+		$this->setHeader('Cc', implode(', ', $cc));
+
+		//      if ($this->handler->getProtocol() === 'smtp')
+		//      {
+		$this->CCArray = $cc;
+		//      }
+
+		return $this;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Set BCC
+	 *
+	 * @param string|array $bcc
+	 * @param integer|null $limit
+	 *
+	 * @return $this
+	 */
+	public function setBCC($bcc, int $limit = null)
+	{
+		if ($limit !== null)
+		{
+			$this->BCCBatchMode = true;
+			$this->BCCBatchSize = $limit;
+		}
+
+		$bcc = $this->cleanEmail($this->stringToArray($bcc));
+
+		if ($this->validate)
+		{
+			$this->validateEmail($bcc);
+		}
+
+		//      if ($this->handler->getProtocol() === 'smtp' ||
+		//              if ($this->BCCBatchMode && count($bcc) > $this->BCCBatchSize)
+		//      {
+		$this->BCCArray = $bcc;
+		//      }
+		//      else
+		//      {
+		$this->setHeader('Bcc', implode(', ', $bcc));
+		//      }
+
+		return $this;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Set Subject
+	 *
+	 * @param string $subject
+	 *
+	 * @return $this
+	 */
+	public function setSubject($subject)
+	{
+		$subject = $this->prepQEncoding($subject);
+		$this->setHeader('Subject', $subject);
+
+		return $this;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Set Body
+	 *
+	 * @param string $body
+	 *
+	 * @return $this
+	 */
+	public function setMessage($body)
+	{
+		$this->body = rtrim(str_replace("\r", '', $body));
+
+		return $this;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Assign file attachments
+	 *
+	 * @param string $file        Can be local path, URL or buffered content
+	 * @param string $disposition 'attachment'
+	 * @param string $newName
+	 * @param string $mime        Not-empty if $file is buffered content
+	 *
+	 * @return $this
+	 */
+	public function attach(string $file, string $disposition = '', string $newName = '', string $mime = '')
+	{
+		if ($mime === '')
+		{
+			if (strpos($file, '://') === false && ! is_file($file))
+			{
+				throw MailerException::forAttachmentMissing($file);
+			}
+
+			if (! $fp = @fopen($file, 'rb'))
+			{
+				throw MailerException::forAttachmentUnreadable($file);
+			}
+
+			$fileContent = stream_get_contents($fp);
+			$mime        = $this->mimeTypes(pathinfo($file, PATHINFO_EXTENSION));
+			fclose($fp);
+		}
+		else
+		{
+			$fileContent = & $file; // buffered file
+		}
+
+		// declare names on their own, to make phpcbf happy
+		$namesAttached       = [
+			$file,
+			$newName,
+		];
+		$this->attachments[] = [
+			'name'        => $namesAttached,
+			'disposition' => empty($disposition) ? 'attachment' : $disposition,
+			// Can also be 'inline'  Not sure if it matters
+			'type'        => $mime,
+			'content'     => chunk_split(base64_encode($fileContent)),
+			'multipart'   => 'mixed',
+		];
+
+		return $this;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Add a Header Item
+	 *
+	 * @param string $header
+	 * @param string $value
+	 *
+	 * @return $this
+	 */
+	public function setHeader($header, $value)
+	{
+		$this->headers[$header] = str_replace(["\n", "\r"], '', $value);
+
+		return $this;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Convert a String to an Array
+	 *
+	 * @param string $email
+	 *
+	 * @return array
+	 */
+	protected function stringToArray($email)
+	{
+		if (! is_array($email))
+		{
+			return (strpos($email, ',') !== false) ? preg_split('/[\s,]/', $email, -1, PREG_SPLIT_NO_EMPTY) : (array) trim($email);
+		}
+
+		return $email;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Set Multipart Value
+	 *
+	 * @param string $str
+	 *
+	 * @return $this
+	 */
+	public function setAltMessage($str)
+	{
+		$this->altMessage = (string) $str;
+
+		return $this;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Set Mailtype
+	 *
+	 * @param string $type
+	 *
+	 * @return $this
+	 */
+	public function setMailType($type = 'text')
+	{
+		$this->mailType = ($type === 'html') ? 'html' : 'text';
+
+		return $this;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Set Wordwrap
+	 *
+	 * @param boolean $wordWrap
+	 *
+	 * @return $this
+	 */
+	public function setWordWrap($wordWrap = true)
+	{
+		$this->wordWrap = (bool) $wordWrap;
+
+		return $this;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Set Priority
+	 *
+	 * @param integer $n
+	 *
+	 * @return $this
+	 */
+	public function setPriority($n = 3)
+	{
+		$this->priority = preg_match('/^[1-5]$/', $n) ? (int) $n : 3;
+
+		return $this;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Set Newline Character
+	 *
+	 * @param string $newline
+	 *
+	 * @return $this
+	 */
+	public function setNewline($newline = "\n")
+	{
+		$this->newline = in_array($newline, ["\n", "\r\n", "\r"]) ? $newline : "\n";
+
+		return $this;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Set CRLF
+	 *
+	 * @param string $CRLF
+	 *
+	 * @return $this
+	 */
+	public function setCRLF($CRLF = "\n")
+	{
+		$this->CRLF = ($CRLF !== "\n" && $CRLF !== "\r\n" && $CRLF !== "\r") ? "\n" : $CRLF;
+
+		return $this;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Set RFC 822 Date
+	 *
+	 * @return string
+	 */
+	protected function setDate()
+	{
+		$timezone = date('Z');
+		$operator = ($timezone[0] === '-') ? '-' : '+';
+		$timezone = abs($timezone);
+		$timezone = floor($timezone / 3600) * 100 + ($timezone % 3600) / 60;
+
+		return sprintf('%s %s%04d', date('D, j M Y H:i:s'), $operator, $timezone);
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Validate Email Address(es)
+	 *
+	 * @param string|array $email
+	 *
+	 * @return boolean
+	 */
+	public function validateEmail($email)
+	{
+		if (! is_array($email))
+		{
+			$email = [$email];
+		}
+
+		foreach ($email as $val)
+		{
+			if (! $this->isValidEmail($val))
+			{
+				throw MailerException::forInvalidAddress($val);
+			}
+		}
+
+		return true;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Email Validation
+	 *
+	 * @param string $email
+	 *
+	 * @return boolean
+	 */
+	public function isValidEmail($email)
+	{
+		$email = $this->cleanEMail($email);
+
+		// sanitize the domain name
+		$atpos = strpos($email, '@');
+		$email = mb_substr($email, 0, ++ $atpos, '8bit') . idn_to_ascii(
+						mb_substr($email, $atpos), 0, INTL_IDNA_VARIANT_UTS46
+		);
+
+		return (bool) filter_var($email, FILTER_VALIDATE_EMAIL);
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Clean Extended Email Address: Joe Smith <joe@smith.com>
+	 *
+	 * @param string|array $email An email string, or array of them
+	 *
+	 * @return string|array The "clean" email-only address(es)
+	 */
+	public function cleanEmail($email)
+	{
+		if (! is_array($email))
+		{
+			return preg_match('/\<(.*)\>/', $email, $match) ? $match[1] : $email;
+		}
+
+		$cleanEmail = [];
+
+		foreach ($email as $addy)
+		{
+			$cleanEmail[] = preg_match('/\<(.*)\>/', $addy, $match) ? $match[1] : $addy;
+		}
+
+		return $cleanEmail;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Word Wrap
+	 *
+	 * @param string       $str
+	 * @param integer|null $charlim Line-length limit
+	 *
+	 * @return string
+	 */
+	public function wordWrap($str, $charlim = null)
+	{
+		// Set the character limit, if not already present
+		if (empty($charlim))
+		{
+			$charlim = empty($this->wrapChars) ? 76 : $this->wrapChars;
+		}
+
+		// Standardize newlines
+		if (strpos($str, "\r") !== false)
+		{
+			$str = str_replace(["\r\n", "\r"], "\n", $str);
+		}
+
+		// Reduce multiple spaces at end of line
+		$str = preg_replace('| +\n|', "\n", $str);
+
+		// If the current word is surrounded by {unwrap} tags we'll
+		// strip the entire chunk and replace it with a marker.
+		$unwrap = [];
+		if (preg_match_all('|\{unwrap\}(.+?)\{/unwrap\}|s', $str, $matches))
+		{
+			for ($i = 0, $c = count($matches[0]); $i < $c; $i ++)
+			{
+				$unwrap[] = $matches[1][$i];
+				$str      = str_replace($matches[0][$i], '{{unwrapped' . $i . '}}', $str);
+			}
+		}
+
+		// Use PHP's native function to do the initial wordwrap.
+		// We set the cut flag to FALSE so that any individual words that are
+		// too long get left alone. In the next step we'll deal with them.
+		$str = wordwrap($str, $charlim, "\n", false);
+
+		// Split the string into individual lines of text and cycle through them
+		$output = '';
+		foreach (explode("\n", $str) as $line)
+		{
+			// Is the line within the allowed character count?
+			// If so we'll join it to the output and continue
+			if (mb_strlen($line) <= $charlim)
+			{
+				$output .= $line . $this->newline;
+				continue;
+			}
+
+			$temp = '';
+			do
+			{
+				// If the over-length word is a URL we won't wrap it
+				if (preg_match('!\[url.+\]|://|www\.!', $line))
+				{
+					break;
+				}
+
+				// Trim the word down
+				$temp .= mb_substr($line, 0, $charlim - 1, '8bit');
+				$line  = mb_substr($line, $charlim - 1);
+			}
+			while (mb_strlen($line) > $charlim);
+
+			// If $temp contains data it means we had to split up an over-length
+			// word into smaller chunks so we'll add it back to our current line
+			if ($temp !== '')
+			{
+				$output .= $temp . $this->newline;
+			}
+
+			$output .= $line . $this->newline;
+		}
+
+		// Put our markers back
+		if ($unwrap)
+		{
+			foreach ($unwrap as $key => $val)
+			{
+				$output = str_replace('{{unwrapped' . $key . '}}', $val, $output);
+			}
+		}
+
+		return $output;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Send the message
+	 *
+	 * @param boolean $autoClear
+	 * @param boolean $reallySend
+	 *
+	 * @return boolean
+	 */
+	public function send($autoClear = true, bool $reallySend = true)
+	{
+		// our decision here, whether to send or fake it
+		$result = $reallySend ? $this->handler->send($this, $autoClear) : true;
+
+		if ($result && $autoClear)
+		{
+			$this->clear();
+		}
+
+		return $result;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Mime Types
+	 *
+	 * @param string $ext
+	 *
+	 * @return string
+	 */
+	protected function mimeTypes($ext = '')
+	{
+		$mime = Mimes::guessTypeFromExtension(strtolower($ext));
+
+		return ! empty($mime) ? $mime : 'application/x-unknown-content-type';
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Lookup an email header and return its value.
+	 *
+	 * @param string $key
+	 *
+	 * @return string|null
+	 */
+	public function getHeader(string $key = ''): ?string
+	{
+		return $this->headers[$key] ?? null;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Magic method to all protected/private class properties to be easily set,
+	 * if a property has a setter method.
+	 *
+	 * @param string $key
+	 * @param null   $value
+	 *
+	 * @return $this
+	 */
+	public function __set(string $key, $value = null)
+	{
+		$method = 'set' . str_replace(' ', '', ucwords(str_replace(['-', '_'], ' ', $key)));
+		if (method_exists($this, $method))
+		{
+			$this->$method($value);
+		}
+
+		return $this;
+	}
+
+	/**
+	 * Magic method to allow retrieval of protected
+	 * class properties either by their name, or through a `getCamelCasedProperty()`
+	 * method.
+	 *
+	 * @param string $key
+	 *
+	 * @return mixed
+	 */
+	public function __get(string $key)
+	{
+		// Convert to CamelCase for the method
+		$method = 'get' . str_replace(' ', '', ucwords(str_replace(['-', '_'], ' ', $key)));
+		if (method_exists($this, $method))
+		{
+			$result = $this->$method();
+		}
+		else if (property_exists($this, $key))
+		{
+			$result = $this->$key;
+		}
+
+		return $result ?? null;
+	}
+
+}
diff --git a/tests/_support/Mailer/ci-logo-not-readable.png b/tests/_support/Mailer/ci-logo-not-readable.png
new file mode 100644
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diff --git a/tests/_support/Mailer/ci-logo.png b/tests/_support/Mailer/ci-logo.png
new file mode 100644
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GIT binary patch
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diff --git a/tests/system/Config/ServicesTest.php b/tests/system/Config/ServicesTest.php
index 14fbd27a2910..2cbf656aa6f3 100644
--- a/tests/system/Config/ServicesTest.php
+++ b/tests/system/Config/ServicesTest.php
@@ -28,6 +28,7 @@
 use CodeIgniter\HTTP\URI;
 use CodeIgniter\Images\ImageHandlerInterface;
 use CodeIgniter\Language\Language;
+use CodeIgniter\Mailer\MailerInterface;
 use CodeIgniter\Pager\Pager;
 use CodeIgniter\Router\RouteCollection;
 use CodeIgniter\Router\Router;
@@ -124,6 +125,18 @@ public function testNewUnsharedEmailWithNonEmptyConfig()
         $this->assertInstanceOf(Email::class, $actual);
     }
 
+    public function testNewMailer()
+    {
+        $actual = Services::mailer();
+        $this->assertInstanceOf(MailerInterface::class, $actual);
+    }
+
+    public function testNewUnsharedMailer()
+    {
+        $actual = Services::mailer(null, false);
+        $this->assertInstanceOf(MailerInterface::class, $actual);
+    }
+
     public function testNewExceptions()
     {
         $actual = Services::exceptions(new Exceptions(), Services::request(), Services::response());
diff --git a/tests/system/Mailer/MailerTest.php b/tests/system/Mailer/MailerTest.php
new file mode 100644
index 000000000000..02eb92321407
--- /dev/null
+++ b/tests/system/Mailer/MailerTest.php
@@ -0,0 +1,579 @@
+<?php namespace CodeIgniter\Mailer;
+
+use CodeIgniter\Test\CIUnitTestCase;
+
+class MailerTest extends CIUnitTestCase
+{
+	public function tearDown()
+	{
+		// Restore file permissions after unreadable attachment test
+		$thefile = SUPPORTPATH . 'Mailer/ci-logo-not-readable.png';
+		chmod($thefile, 0664);
+	}
+
+	//--------------------------------------------------------------------
+	// Test constructor & configs
+
+	public function testDefaultWithCustomConfig()
+	{
+		$mailer = new Mailer(['validate' => true, 'truth' => 'out there']);
+		$this->assertTrue($mailer->wordWrap);
+		$this->assertEquals(76, $mailer->wrapChars);
+		$this->assertEquals('text', $mailer->mailType);
+		$this->assertEquals('UTF-8', $mailer->charset);
+		$this->assertEquals('', $mailer->altMessage);
+		$this->assertTrue($mailer->validate);
+		$this->assertNull($mailer->truth);
+	}
+
+	public function testDefaultWithEmptyConfig()
+	{
+		$mailer = new Mailer();
+		$this->assertTrue($mailer->wordWrap);
+		$this->assertEquals(76, $mailer->wrapChars);
+		$this->assertEquals('text', $mailer->mailType);
+		$this->assertEquals('UTF-8', $mailer->charset);
+		$this->assertEquals('', $mailer->altMessage);
+		$this->assertFalse($mailer->validate); // this one differs
+		$this->assertNull($mailer->truth);
+	}
+
+	//--------------------------------------------------------------------
+	// Test setting the "from" property
+
+	public function testSetFromMailerOnly()
+	{
+		$mailer = new Mailer();
+		$mailer->setFrom('leia@alderaan.org');
+		$this->assertEquals(' <leia@alderaan.org>', $mailer->getHeader('From'));
+		$this->assertEquals('<leia@alderaan.org>', $mailer->getHeader('Return-Path'));
+	}
+
+	public function testSetFromMailerAndName()
+	{
+		$mailer = new Mailer();
+		$mailer->setFrom('leia@alderaan.org', 'Princess Leia');
+		$this->assertEquals('"Princess Leia" <leia@alderaan.org>', $mailer->getHeader('From'));
+		$this->assertEquals('<leia@alderaan.org>', $mailer->getHeader('Return-Path'));
+	}
+
+	public function testSetFromMailerAndFunkyName()
+	{
+		$mailer = new Mailer();
+		$mailer->setFrom('<leia@alderaan.org>', 'Princess Leià');
+		$this->assertEquals('=?UTF-8?Q?Princess=20Lei=C3=A0?= <leia@alderaan.org>', $mailer->getHeader('From'));
+		$this->assertEquals('<leia@alderaan.org>', $mailer->getHeader('Return-Path'));
+	}
+
+	public function testSetFromWithValidation()
+	{
+		$mailer = new Mailer(['validation' => true]);
+		$mailer->setFrom('leia@alderaan.org', 'Princess Leia');
+		$this->assertEquals('"Princess Leia" <leia@alderaan.org>', $mailer->getHeader('From'));
+		$this->assertEquals('<leia@alderaan.org>', $mailer->getHeader('Return-Path'));
+	}
+
+	public function testSetFromWithValidationAndReturnPath()
+	{
+		$mailer = new Mailer(['validation' => true]);
+		$mailer->setFrom('leia@alderaan.org', 'Princess Leia', 'leia@alderaan.org');
+		$this->assertEquals('"Princess Leia" <leia@alderaan.org>', $mailer->getHeader('From'));
+		$this->assertEquals('<leia@alderaan.org>', $mailer->getHeader('Return-Path'));
+	}
+
+	public function testSetFromWithValidationAndDifferentReturnPath()
+	{
+		$mailer = new Mailer(['validation' => true]);
+		$mailer->setFrom('leia@alderaan.org', 'Princess Leia', 'padme@naboo.org');
+		$this->assertEquals('"Princess Leia" <leia@alderaan.org>', $mailer->getHeader('From'));
+		$this->assertEquals('<padme@naboo.org>', $mailer->getHeader('Return-Path'));
+	}
+
+	//--------------------------------------------------------------------
+	// Test setting the "replyTo" property
+
+	public function testSetReplyToMailerOnly()
+	{
+		$mailer = new Mailer();
+		$mailer->setReplyTo('leia@alderaan.org');
+		$this->assertEquals(' <leia@alderaan.org>', $mailer->getHeader('Reply-To'));
+	}
+
+	public function testSetReplyToMailerAndName()
+	{
+		$mailer = new Mailer();
+		$mailer->setReplyTo('leia@alderaan.org', 'Princess Leia');
+		$this->assertEquals('"Princess Leia" <leia@alderaan.org>', $mailer->getHeader('Reply-To'));
+	}
+
+	public function testSetReplyToMailerAndFunkyName()
+	{
+		$mailer = new Mailer();
+		$mailer->setReplyTo('<leia@alderaan.org>', 'Princess Leià');
+		$this->assertEquals('=?UTF-8?Q?Princess=20Lei=C3=A0?= <leia@alderaan.org>', $mailer->getHeader('Reply-To'));
+	}
+
+	public function testSetReplyToWithValidation()
+	{
+		$mailer = new Mailer(['validation' => true]);
+		$mailer->setReplyTo('leia@alderaan.org', 'Princess Leia');
+		$this->assertEquals('"Princess Leia" <leia@alderaan.org>', $mailer->getHeader('Reply-To'));
+	}
+
+	public function testSetReplyToWithValidationAndReturnPath()
+	{
+		$mailer = new Mailer(['validation' => true]);
+		$mailer->setReplyTo('leia@alderaan.org', 'Princess Leia', 'leia@alderaan.org');
+		$this->assertEquals('"Princess Leia" <leia@alderaan.org>', $mailer->getHeader('Reply-To'));
+	}
+
+	public function testSetReplyToWithValidationAndDifferentReturnPath()
+	{
+		$mailer = new Mailer(['validation' => true]);
+		$mailer->setReplyTo('leia@alderaan.org', 'Princess Leia', 'padme@naboo.org');
+		$this->assertEquals('"Princess Leia" <leia@alderaan.org>', $mailer->getHeader('Reply-To'));
+	}
+
+	//--------------------------------------------------------------------
+	// Test setting the "to" property (recipients)
+
+	public function testSetToBasic()
+	{
+		$mailer = new Mailer();
+		$mailer->setTo('Luke <luke@tatooine.org>');
+		$this->assertTrue(in_array('luke@tatooine.org', $mailer->recipients));
+	}
+
+	public function testSetToArray()
+	{
+		$mailer = new Mailer();
+		$mailer->setTo(['Luke <luke@tatooine.org>', 'padme@naboo.org']);
+		$this->assertTrue(in_array('luke@tatooine.org', $mailer->recipients));
+		$this->assertTrue(in_array('padme@naboo.org', $mailer->recipients));
+	}
+
+	public function testSetToValid()
+	{
+		$mailer = new Mailer(['validate' => true]);
+		$mailer->setTo('Luke <luke@tatooine.org>');
+		$this->assertTrue(in_array('luke@tatooine.org', $mailer->recipients));
+	}
+
+	public function testSetToInvalid()
+	{
+		$mailer = new Mailer(['validate' => false]);
+		$mailer->setTo('Luke <luke@tatooine>');
+		$this->assertTrue(in_array('luke@tatooine', $mailer->recipients));
+	}
+
+	/**
+	 * @expectedException \CodeIgniter\Mailer\Exceptions\MailerException
+	 */
+	public function testDontSetToInvalid()
+	{
+		$mailer = new Mailer(['validate' => true]);
+		$mailer->setTo('Luke <luke@tatooine>');
+	}
+
+	public function testSetToHeader()
+	{
+		$mailer = new Mailer(['validate' => true]);
+		$mailer->setProtocol('sendmail');
+		$mailer->setTo('Luke <luke@tatooine.org>');
+		$this->assertTrue(in_array('luke@tatooine.org', $mailer->recipients));
+		$this->assertEquals('luke@tatooine.org', $mailer->getHeader('To'));
+	}
+
+	//--------------------------------------------------------------------
+	// Test setting the "cc" property (copied recipients)
+
+	public function testSetCCBasic()
+	{
+		$mailer = new Mailer();
+		$mailer->setCC('Luke <luke@tatooine.org>');
+		$this->assertTrue(in_array('luke@tatooine.org', $mailer->CCArray));
+	}
+
+	public function testSetCCArray()
+	{
+		$mailer = new Mailer();
+		$mailer->setCC(['Luke <luke@tatooine.org>', 'padme@naboo.org']);
+		$this->assertTrue(in_array('luke@tatooine.org', $mailer->CCArray));
+		$this->assertTrue(in_array('padme@naboo.org', $mailer->CCArray));
+		$this->assertEquals('luke@tatooine.org, padme@naboo.org', $mailer->getHeader('Cc'));
+	}
+
+	public function testSetCCValid()
+	{
+		$mailer = new Mailer(['validate' => true]);
+		$mailer->setCC('Luke <luke@tatooine.org>');
+		$this->assertTrue(in_array('luke@tatooine.org', $mailer->CCArray));
+	}
+
+	public function testSetCCInvalid()
+	{
+		$mailer = new Mailer(['validate' => false]);
+		$mailer->setCC('Luke <luke@tatooine>');
+		$this->assertTrue(in_array('luke@tatooine', $mailer->CCArray));
+	}
+
+	/**
+	 * @expectedException \CodeIgniter\Mailer\Exceptions\MailerException
+	 */
+	public function testDontSetCCInvalid()
+	{
+		$mailer = new Mailer(['validate' => true]);
+		$mailer->setCC('Luke <luke@tatooine>');
+	}
+
+	public function testSetCCHeader()
+	{
+		$mailer = new Mailer(['validate' => true]);
+		$mailer->setCC('Luke <luke@tatooine.org>');
+		$this->assertTrue(in_array('luke@tatooine.org', $mailer->CCArray));
+		$this->assertEquals('luke@tatooine.org', $mailer->getHeader('Cc'));
+	}
+
+	public function testSetCCForSMTP()
+	{
+		$mailer = new Mailer(['validate' => true]);
+		$mailer->setProtocol('smtp');
+		$mailer->setCC('Luke <luke@tatooine.org>');
+		$this->assertTrue(in_array('luke@tatooine.org', $mailer->CCArray));
+		$this->assertEquals('luke@tatooine.org', $mailer->getHeader('Cc'));
+	}
+
+	//--------------------------------------------------------------------
+	// Test setting the "bcc" property (blind-copied recipients)
+
+	public function testSetBCCBasic()
+	{
+		$mailer = new Mailer();
+		$mailer->setBCC('Luke <luke@tatooine.org>');
+		$this->assertTrue(in_array('luke@tatooine.org', $mailer->BCCArray));
+	}
+
+	public function testSetBCCArray()
+	{
+		$mailer = new Mailer();
+		$mailer->setBCC(['Luke <luke@tatooine.org>', 'padme@naboo.org']);
+		$this->assertTrue(in_array('luke@tatooine.org', $mailer->BCCArray));
+		$this->assertTrue(in_array('padme@naboo.org', $mailer->BCCArray));
+		$this->assertEquals('luke@tatooine.org, padme@naboo.org', $mailer->getHeader('Bcc'));
+	}
+
+	public function testSetBCCValid()
+	{
+		$mailer = new Mailer(['validate' => true]);
+		$mailer->setBCC('Luke <luke@tatooine.org>');
+		$this->assertTrue(in_array('luke@tatooine.org', $mailer->BCCArray));
+	}
+
+	public function testSetBCCInvalid()
+	{
+		$mailer = new Mailer(['validate' => false]);
+		$mailer->setBCC('Luke <luke@tatooine>');
+		$this->assertTrue(in_array('luke@tatooine', $mailer->BCCArray));
+	}
+
+	/**
+	 * @expectedException \CodeIgniter\Mailer\Exceptions\MailerException
+	 */
+	public function testDontSetBCCInvalid()
+	{
+		$mailer = new Mailer(['validate' => true]);
+		$mailer->setBCC('Luke <luke@tatooine>');
+	}
+
+	public function testSetBCCHeader()
+	{
+		$mailer = new Mailer(['validate' => true]);
+		$mailer->setBCC('Luke <luke@tatooine.org>');
+		$this->assertTrue(in_array('luke@tatooine.org', $mailer->BCCArray));
+		$this->assertEquals('luke@tatooine.org', $mailer->getHeader('Bcc'));
+	}
+
+	public function testSetBCCForSMTP()
+	{
+		$mailer = new Mailer(['validate' => true]);
+		$mailer->setProtocol('smtp');
+		$mailer->setBCC('Luke <luke@tatooine.org>');
+		$this->assertTrue(in_array('luke@tatooine.org', $mailer->BCCArray));
+		$this->assertEquals('luke@tatooine.org', $mailer->getHeader('Bcc'));
+	}
+
+	public function testSetBCCBatch()
+	{
+		$mailer = new Mailer();
+		$mailer->setBCC(['Luke <luke@tatooine.org>', 'padme@naboo.org'], 2);
+		$this->assertTrue(in_array('luke@tatooine.org', $mailer->BCCArray));
+		$this->assertTrue(in_array('padme@naboo.org', $mailer->BCCArray));
+		$this->assertEquals('luke@tatooine.org, padme@naboo.org', $mailer->getHeader('Bcc'));
+	}
+
+	public function testSetBCCBiggerBatch()
+	{
+		$mailer = new Mailer();
+		$mailer->setBCC(['Luke <luke@tatooine.org>', 'padme@naboo.org', 'leia@alderaan.org'], 2);
+		$this->assertTrue(in_array('luke@tatooine.org', $mailer->BCCArray));
+		$this->assertTrue(in_array('padme@naboo.org', $mailer->BCCArray));
+		$this->assertEquals('luke@tatooine.org, padme@naboo.org, leia@alderaan.org', $mailer->getHeader('Bcc'));
+	}
+
+	//--------------------------------------------------------------------
+	// Test setting the subject
+
+	public function testSetSubject()
+	{
+		$mailer    = new Mailer();
+		$original = 'Just a silly love song';
+		$expected = '=?UTF-8?Q?Just=20a=20silly=20love=20so?==?UTF-8?Q?ng?=';
+		$mailer->setSubject($original);
+		$this->assertEquals($expected, $mailer->getHeader('Subject'));
+	}
+
+	public function testSetEncodedSubject()
+	{
+		$mailer    = new Mailer();
+		$original = 'Just a silly Leià song';
+		$expected = '=?UTF-8?Q?Just=20a=20silly=20Lei=C3=A0=20s?==?UTF-8?Q?ong?=';
+		$mailer->setSubject($original);
+		$this->assertEquals($expected, $mailer->getHeader('Subject'));
+	}
+
+	//--------------------------------------------------------------------
+	// Test setting the body
+
+	public function testSetMessage()
+	{
+		$mailer    = new Mailer();
+		$original = 'Just a silly love song';
+		$expected = $original;
+		$mailer->setMessage($original);
+		$this->assertEquals($expected, $mailer->body);
+	}
+
+	public function testSetMultilineMessage()
+	{
+		$mailer    = new Mailer();
+		$original = "Just a silly love song\r\nIt's just two lines long";
+		$expected = "Just a silly love song\nIt's just two lines long";
+		$mailer->setMessage($original);
+		$this->assertEquals($expected, $mailer->body);
+	}
+
+	//--------------------------------------------------------------------
+	// Test setting the alternate message
+
+	public function testSetAltMessage()
+	{
+		$mailer    = new Mailer();
+		$original = 'Just a silly love song';
+		$expected = $original;
+		$mailer->setAltMessage($original);
+		$this->assertEquals($expected, $mailer->altMessage);
+	}
+
+	public function testSetMultilineAltMessage()
+	{
+		$mailer    = new Mailer();
+		$original = "Just a silly love song\r\nIt's just two lines long";
+		$mailer->setAltMessage($original);
+		$this->assertEquals($original, $mailer->altMessage);
+	}
+
+	//--------------------------------------------------------------------
+	// Test clearing the email
+
+	public function testClearing()
+	{
+		$mailer = new Mailer();
+		$mailer->setFrom('leia@alderaan.org');
+		$this->assertEquals(' <leia@alderaan.org>', $mailer->getHeader('From'));
+		$mailer->setTo('luke@tatooine.org');
+		$this->assertTrue(in_array('luke@tatooine.org', $mailer->recipients));
+
+		$mailer->clear(true);
+		$this->assertEquals('', $mailer->getHeader('From'));
+		$this->assertEquals('', $mailer->getHeader('To'));
+
+		$mailer->setFrom('leia@alderaan.org');
+		$this->assertEquals(' <leia@alderaan.org>', $mailer->getHeader('From'));
+	}
+
+	//--------------------------------------------------------------------
+	// Test clearing the email
+
+	public function testAttach()
+	{
+		$mailer = new Mailer();
+		$mailer->setFrom('leia@alderaan.org');
+		$mailer->setTo('luke@tatooine.org');
+
+		$mailer->attach(SUPPORTPATH . 'Images/ci-logo.png');
+		$this->assertEquals(1, count($mailer->attachments));
+	}
+
+	/**
+	 * @expectedException \CodeIgniter\Mailer\Exceptions\MailerException
+	 */
+	public function testAttachNotThere()
+	{
+		$mailer = new Mailer();
+		$mailer->setFrom('leia@alderaan.org');
+		$mailer->setTo('luke@tatooine.org');
+
+		$mailer->attach(SUPPORTPATH . 'Mailer/ci-logo-not-there.png');
+		$this->assertEquals(1, count($mailer->attachments));
+	}
+
+	/**
+	 * @expectedException \CodeIgniter\Mailer\Exceptions\MailerException
+	 */
+	public function testAttachNotReadable()
+	{
+		$mailer = new Mailer();
+		$mailer->setFrom('leia@alderaan.org');
+		$mailer->setTo('luke@tatooine.org');
+
+		$thefile = SUPPORTPATH . 'Mailer/ci-logo-not-readable.png';
+		chmod($thefile, 0222);
+		$mailer->attach($thefile);
+	}
+
+	public function testAttachContent()
+	{
+		$mailer = new Mailer();
+		$mailer->setFrom('leia@alderaan.org');
+		$mailer->setTo('luke@tatooine.org');
+
+		$content = 'This is bogus content';
+		$mailer->attach($content, '', 'truelies.txt', 'text/html');
+		$this->assertEquals(1, count($mailer->attachments));
+	}
+
+	//--------------------------------------------------------------------
+	// Test changing the protocol
+
+	public function testSetProtocol()
+	{
+		$mailer = new Mailer();
+		$this->assertEquals('mail', $mailer->getProtocol()); // default
+		$mailer->setProtocol('smtp');
+		$this->assertEquals('smtp', $mailer->getProtocol());
+		$mailer->setProtocol('mail');
+		$this->assertEquals('mail', $mailer->getProtocol());
+	}
+
+	/**
+	 * @expectedException \CodeIgniter\Mailer\Exceptions\MailerException
+	 */
+	public function testSetBadProtocol()
+	{
+		$mailer = new Mailer();
+		$mailer->setProtocol('mind-reader');
+	}
+
+	//--------------------------------------------------------------------
+	// Test word wrap
+
+	public function testWordWrapVanilla()
+	{
+		$mailer    = new Mailer();
+		$original = 'This is a short line.';
+		$expected = $original;
+		$this->assertEquals($expected, rtrim($mailer->wordWrap($original)));
+	}
+
+	public function testWordWrapShortLines()
+	{
+		$mailer    = new Mailer();
+		$original = 'This is a short line.';
+		$expected = "This is a short\r\nline.";
+		$this->assertEquals($expected, rtrim($mailer->wordWrap($original, 16)));
+	}
+
+	public function testWordWrapLines()
+	{
+		$mailer    = new Mailer();
+		$original = "This is a\rshort line.";
+		$expected = "This is a\r\nshort line.";
+		$this->assertEquals($expected, rtrim($mailer->wordWrap($original)));
+	}
+
+	public function testWordWrapUnwrap()
+	{
+		$mailer    = new Mailer();
+		$original = 'This is a {unwrap}not so short{/unwrap} line.';
+		$expected = 'This is a not so short line.';
+		$this->assertEquals($expected, rtrim($mailer->wordWrap($original)));
+	}
+
+	public function testWordWrapUnwrapWrapped()
+	{
+		$mailer    = new Mailer();
+		$original = 'This is a {unwrap}not so short or something{/unwrap} line.';
+		$expected = "This is a\r\nnot so short or something\r\nline.";
+		$this->assertEquals($expected, rtrim($mailer->wordWrap($original, 16)));
+	}
+
+	public function testWordWrapConsolidate()
+	{
+		$mailer    = new Mailer();
+		$original = "This is\r\na not so short or something\r\nline.";
+		$expected = "This is\r\na not so short\r\nor something\r\nline.";
+		$this->assertEquals($expected, rtrim($mailer->wordWrap($original, 16)));
+	}
+
+	public function testWordWrapLongWord()
+	{
+		$mailer    = new Mailer();
+		$original = "This is part of interoperabilities isn't it?";
+		$expected = "This is part of\r\ninteroperabilit\r\nies\r\nisn't it?";
+		$this->assertEquals($expected, rtrim($mailer->wordWrap($original, 16)));
+	}
+
+	public function testWordWrapURL()
+	{
+		$mailer    = new Mailer();
+		$original = "This is part of http://interoperabilities.com isn't it?";
+		$expected = "This is part of\r\nhttp://interoperabilities.com\r\nisn't it?";
+		$this->assertEquals($expected, rtrim($mailer->wordWrap($original, 16)));
+	}
+
+	//--------------------------------------------------------------------
+	// Test support methods
+
+	public function testValidMailer()
+	{
+		$mailer = new Mailer();
+		$this->assertTrue($mailer->isValidMailer('"Princess Leia" <leia@alderaan.org>'));
+		$this->assertTrue($mailer->isValidMailer('leia@alderaan.org'));
+		$this->assertTrue($mailer->isValidMailer('<princess.leia@alderaan.org>'));
+		$this->assertFalse($mailer->isValidMailer('<leia_at_alderaan.org>'));
+		$this->assertFalse($mailer->isValidMailer('<leia@alderaan>'));
+		$this->assertFalse($mailer->isValidMailer('<leia.alderaan@org>'));
+	}
+
+	public function testMagicMethods()
+	{
+		$mailer           = new Mailer();
+		$mailer->protocol = 'mail';
+		$this->assertEquals('mail', $mailer->protocol);
+	}
+
+	//--------------------------------------------------------------------
+	// "Test" sending the email
+
+	public function testFakeSend()
+	{
+		$mailer = new Mailer();
+		$mailer->setFrom('leia@alderaan.org');
+		$mailer->setTo('Luke <luke@tatooine>');
+		$mailer->setSubject('Hi there');
+
+		// make sure the second parameter below is "false"
+		// or you will trigger email for real!
+		$this->assertTrue($mailer->send(true, false));
+	}
+}

From 71d748308c5ef99407e5422ebcbfcc2f9ccdc565 Mon Sep 17 00:00:00 2001
From: MGatner <mgatner@icloud.com>
Date: Tue, 1 Jun 2021 01:04:18 +0000
Subject: [PATCH 2/8] Implement Address and Email

---
 app/Config/Mailer.php               | 157 +-------------
 system/Config/Services.php          |   7 +-
 system/Mailer/Address.php           | 141 +++++++++++++
 system/Mailer/Email.php             | 310 ++++++++++++++++++++++++++++
 system/Mailer/MailerInterface.php   |   8 +-
 tests/system/Mailer/AddressTest.php | 137 ++++++++++++
 tests/system/Mailer/EmailTest.php   |  18 ++
 7 files changed, 617 insertions(+), 161 deletions(-)
 create mode 100644 system/Mailer/Address.php
 create mode 100644 system/Mailer/Email.php
 create mode 100644 tests/system/Mailer/AddressTest.php
 create mode 100644 tests/system/Mailer/EmailTest.php

diff --git a/app/Config/Mailer.php b/app/Config/Mailer.php
index b6969cde9713..2e0ff0fdb4a0 100644
--- a/app/Config/Mailer.php
+++ b/app/Config/Mailer.php
@@ -5,164 +5,17 @@
 class Mailer
 {
 	/**
-	 * @var string
-	 */
-	public $fromEmail;
-
-	/**
-	 * @var string
-	 */
-	public $fromName;
-
-	/**
-	 * Enable word-wrap
-	 *
-	 * @var boolean
-	 */
-	public $wordWrap = true;
-
-	/**
-	 * Character count to wrap at
-	 *
-	 * @var integer
-	 */
-	public $wrapChars = 76;
-
-	/**
-	 * Type of mail, either 'text' or 'html'
-	 *
-	 * @var string
-	 */
-	public $mailType = 'text';
-
-	/**
-	 * Character set (utf-8, iso-8859-1, etc.)
-	 *
-	 * @var string
-	 */
-	public $charset = 'UTF-8';
-
-	/**
-	 * Whether to validate the email address
+	 * Default "from" address.
 	 *
-	 * @var boolean
+	 * @var string|null
 	 */
-	public $validate = false;
+	public $from;
 
 	/**
-	 * Email Priority. 1 = highest. 5 = lowest. 3 = normal
+	 * Default email priority.
+	 * 1 = highest, 3 = normal, 5 = lowest
 	 *
 	 * @var integer
 	 */
 	public $priority = 3;
-
-	/**
-	 * Newline character. (Use “\r\n” to comply with RFC 822)
-	 *
-	 * @var string
-	 */
-	public $CRLF = "\r\n";
-
-	/**
-	 * Newline character. (Use “\r\n” to comply with RFC 822)
-	 *
-	 * @var string
-	 */
-	public $newline = "\r\n";
-
-	/**
-	 * Enable BCC Batch Mode.
-	 *
-	 * @var boolean
-	 */
-	public $BCCBatchMode = false;
-
-	/**
-	 * Number of emails in each BCC batch
-	 *
-	 * @var integer
-	 */
-	public $BCCBatchSize = 200;
-
-	/**
-	 * Enable notify message from server
-	 *
-	 * @var boolean
-	 */
-	public $DSN = false;
-
-	//-------------------------------------------------------
-	// Mailer properties
-	//-------------------------------------------------------
-
-	/**
-	 * The "user agent"
-	 *
-	 * @var string
-	 */
-	public $userAgent = 'CodeIgniter';
-
-	/**
-	 * The mail sending protocol: mail, sendmail, smtp
-	 *
-	 * @var string
-	 */
-	public $protocol = 'mail';
-
-	/**
-	 * The server path to Sendmail.
-	 *
-	 * @var string
-	 */
-	public $mailPath = '/usr/sbin/sendmail';
-
-	/**
-	 * SMTP Server Address
-	 *
-	 * @var string
-	 */
-	public $SMTPHost;
-
-	/**
-	 * SMTP Username
-	 *
-	 * @var string
-	 */
-	public $SMTPUser;
-
-	/**
-	 * SMTP Password
-	 *
-	 * @var string
-	 */
-	public $SMTPPass;
-
-	/**
-	 * SMTP Port
-	 *
-	 * @var integer
-	 */
-	public $SMTPPort = 25;
-
-	/**
-	 * SMTP Timeout (in seconds)
-	 *
-	 * @var integer
-	 */
-	public $SMTPTimeout = 5;
-
-	/**
-	 * Enable persistent SMTP connections
-	 *
-	 * @var boolean
-	 */
-	public $SMTPKeepAlive = false;
-
-	/**
-	 * SMTP Encryption. Either tls or ssl
-	 *
-	 * @var string
-	 */
-	public $SMTPCrypto = 'tls';
-
 }
diff --git a/system/Config/Services.php b/system/Config/Services.php
index 87fc1210ff5b..ee3e07d0747e 100644
--- a/system/Config/Services.php
+++ b/system/Config/Services.php
@@ -96,7 +96,6 @@
  */
 class Services extends BaseService
 {
-<<<<<<< HEAD
     /**
      * The cache class provides a simple way to store and retrieve
      * complex data for later.
@@ -384,7 +383,7 @@ public static function logger(bool $getShared = true)
         return new Logger(config('Logger'));
     }
 
-	//--------------------------------------------------------------------
+    //--------------------------------------------------------------------
 
     /**
      * The Mailer class lets you send composed messages via mail, sendmail, SMTP.
@@ -394,7 +393,7 @@ public static function logger(bool $getShared = true)
      *
      * @return \CodeIgniter\Mailer\MailerInterface
      */
-    public static function mailer($config = null, bool $getShared = true)
+    public static function mailer(MailerConfig $config = null, bool $getShared = true)
     {
         if ($getShared)
         {
@@ -403,7 +402,7 @@ public static function mailer($config = null, bool $getShared = true)
 
         if (empty($config))
         {
-            $config = new \Config\MailerConfig();
+            $config = new MailerConfig();
         }
 
         $protocolMap = [
diff --git a/system/Mailer/Address.php b/system/Mailer/Address.php
new file mode 100644
index 000000000000..2a2273080c77
--- /dev/null
+++ b/system/Mailer/Address.php
@@ -0,0 +1,141 @@
+<?php
+
+/**
+ * This file is part of the CodeIgniter 4 framework.
+ *
+ * (c) CodeIgniter Foundation <admin@codeigniter.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace CodeIgniter\Mailer;
+
+use InvalidArgumentException;
+
+class Address
+{
+	/**
+	 * @var string
+	 */
+	protected $email;
+
+	/**
+	 * @var string
+	 */
+	protected $name;
+
+	/**
+	 * Creates a new Address from a simple or full email address string.
+	 *
+	 * @param string $address
+	 *
+	 * @return static
+	 */
+	public static function create(string $address)
+	{
+		return new static(...array_values(self::split($address)));
+	}
+
+	/**
+	 * Creates an array of Addresses from an array of inputs.
+	 * Accounts for the niche case of a single CSV of addresses
+	 * @see Email::to()
+	 *
+	 * @param string[] $addresses
+	 *
+	 * @return static[]
+	 */
+	public static function createArray(array $addresses)
+	{
+    	// Check for a CSV first
+    	if (count($addresses) === 1)
+    	{
+    		$element = reset($addresses);
+
+    		if (is_string($element) && strpos($element, ',') !== false)
+	    	{
+    			$addresses = preg_split('/[\s,]/', $element, -1, PREG_SPLIT_NO_EMPTY);
+    		}
+    	}
+
+		return array_map('self::create', $addresses);
+	}
+
+
+	/**
+	 * Parses an address into an email and (optional) display name.
+	 * Trims content but does no validation or encoding.
+	 *
+	 * @param string $address
+	 */
+	final public static function split(string $address): array
+	{
+		if (preg_match('/\<(.*)\>/', $address, $matches))
+		{
+			return [
+				'email' => trim($matches[1]),
+				'name'  => trim(substr($address, 0, -1 * strlen($matches[0])), ' \'"'),
+			];
+		}
+
+		return [
+			'email' => trim($address),
+			'name'  => null,
+		];
+	}
+
+	/**
+	 * Combines an email and (optional) display name into an address.
+	 * Trims content but does no validation or encoding.
+	 *
+	 * @param string $email
+	 * @param string|null $name
+	 */
+	final public static function merge(string $email, string $name = null): string
+	{
+		return empty($name) ? $email : $name . ' <' . $email . '>';
+	}
+
+	/**
+	 * Validates the email and stores the values.
+	 *
+	 * @param string $email
+	 * @param string|null $name
+	 */
+	final public function __construct(string $email, string $name = null)
+	{
+		$this->email = trim($email);
+
+		if (! service('validation')->check($this->email, 'required|valid_email'))
+		{
+			throw new InvalidArgumentException(lang('Mailer.invalidAddress', [$email]));
+		}
+
+		$this->name  = isset($name) ? trim($name, ' \'"') : null;
+	}
+
+	/**
+	 * @return string
+	 */
+	public function getEmail(): string
+	{
+		return $this->email;
+	}
+
+	/**
+	 * @return string|null $name
+	 */
+	public function getName(): ?string
+	{
+		return $this->name;
+	}
+
+	/**
+	 * @return string
+	 */
+	public function __toString(): string
+	{
+		return self::merge($this->email, $this->name);
+	}
+}
diff --git a/system/Mailer/Email.php b/system/Mailer/Email.php
new file mode 100644
index 000000000000..689e57707106
--- /dev/null
+++ b/system/Mailer/Email.php
@@ -0,0 +1,310 @@
+<?php
+
+/**
+ * This file is part of the CodeIgniter 4 framework.
+ *
+ * (c) CodeIgniter Foundation <admin@codeigniter.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace CodeIgniter\Mailer;
+
+use BadMethodCallException;
+use CodeIgniter\I18n\Time;
+use CodeIgniter\HTTP\Message;
+use DateTimeInterface;
+
+/**
+ * Email Class
+ *
+ * Represents a single email message.
+ * This class extends HTTP\Message and uses headers for most storage and retrieval.
+ */
+class Email extends Message
+{
+	private const PRIORITIES = [
+		1 => '1 (Highest)',
+		2 => '2 (High)',
+		3 => '3 (Normal)',
+		4 => '4 (Low)',
+		5 => '5 (Lowest)',
+	];
+
+	/**
+	 * Matches input keys to their setter method to store values.
+	 *
+	 * @param array $data
+	 */
+	public function __construct(array $data = [])
+	{
+		// Check for any keys that match our setters
+		foreach ([
+			'body',
+			'subject',
+			'from',
+			'to',
+			'cc',
+			'bcc',
+			'replyTo',
+			'returnPath',
+			'priority',
+			'date',			
+		] as $method)
+		{
+			if (array_key_exists($method, $data))
+			{
+				$this->$method($data[$method]);
+			}
+		}
+/*
+		// Check for missing defaults and set the config values
+		$config = config('Mailer');
+		if (! array_key_exists('from', $data) && isset($config->from))
+		{
+			$this->from(Address::create($config->from));
+		}
+		if (! array_key_exists('priority', $data))
+		{
+			$this->priority($config->priority);
+		}
+*/
+	}
+
+	//--------------------------------------------------------------------
+	// Setters
+	//--------------------------------------------------------------------
+
+	/**
+	 * Intercepts calls to Message::setBody() to enforce formatting.
+	 *
+	 * @param string $body
+	 *
+	 * @return $this
+	 */
+	public function setBody($body): self
+	{
+		return parent::setBody(rtrim(str_replace("\r", '', $body)));
+	}
+
+	/**
+	 * @param string $body
+	 *
+	 * @return $this
+	 */
+	public function body(string $body)
+	{
+		return $this->setBody($body);
+	}
+
+	/**
+	 * @param string $subject
+	 *
+	 * @return $this
+	 */
+	public function subject(string $subject)
+	{
+	    return $this->setHeader('Subject', $subject);
+	}
+
+	/**
+	 * @param string $address
+	 *
+	 * @return $this
+	 */
+	public function from(string $address)
+	{
+	    return $this->setHeader('From', Address::create($address));
+	}
+
+	/**
+	 * @param Address|string ...$addresses
+	 *
+	 * @return $this
+	 */
+	public function to(...$addresses)
+	{
+	    return $this->setHeader('To', Address::createArray($addresses));
+	}
+
+	/**
+	 * @param Address|string ...$addresses
+	 *
+	 * @return $this
+	 */
+	public function cc(...$addresses)
+	{
+	    return $this->setHeader('Cc', Address::createArray($addresses));
+	}
+
+	/**
+	 * @param Address|string ...$addresses
+	 *
+	 * @return $this
+	 */
+	public function bcc(...$addresses)
+	{
+	    return $this->setHeader('Bcc', Address::createArray($addresses));
+	}
+
+	/**
+	 * @param string $address
+	 *
+	 * @return $this
+	 */
+	public function replyTo(string $address)
+	{
+	    return $this->setHeader('From', Address::create($address));
+	}
+
+	/**
+	 * @param string $address
+	 *
+	 * @return $this
+	 */
+	public function returnPath(string $address)
+	{
+	    return $this->setHeader('Return-Path', Address::create($address));
+	}
+
+	/**
+	 * Sets the priority, where 1 is the highest and 5 is the lowest.
+	 *
+	 * @param int $priority
+	 *
+	 * @return $this
+	 */
+	public function priority(int $priority)
+	{
+		$priority = max($priority, 1);
+		$priority = min($priority, 5);
+
+	    return $this->setHeader('X-Priority', self::PRIORITIES[$priority]);
+	}
+
+	/**
+	 * @return $this
+	 */
+	public function date(DateTimeInterface $date)
+	{
+		return $this->setHeader('Date', (string) Time::createFromInstance($date));
+	}
+
+	//--------------------------------------------------------------------
+	// Getters
+	//--------------------------------------------------------------------
+
+	/**
+	 * @return string|null
+	 */
+	public function getSubject(): ?string
+	{
+		return $this->hasHeader('Subject') ? $this->getHeader('Subject')->getValue() : null;
+	}
+
+	/**
+	 * @return Address|null
+	 */
+	public function getFrom(): ?Address
+	{
+		return $this->hasHeader('From') ? Address::create($this->getHeader('From')->getValue()) : null;
+	}
+
+	/**
+	 * @return Address[]|null
+	 */
+	public function getTo(): ?array
+	{
+		return $this->hasHeader('To') ? Address::createArray($this->getHeader('To')->getValue()) : null;
+	}
+
+	/**
+	 * @return Address[]|null
+	 */
+	public function getCc(): ?array
+	{
+		return $this->hasHeader('Cc') ? Address::createArray($this->getHeader('Cc')->getValue()) : null;
+	}
+
+	/**
+	 * @return Address[]|null
+	 */
+	public function getBcc(): ?array
+	{
+		return $this->hasHeader('Bcc') ? Address::createArray($this->getHeader('Bcc')->getValue()) : null;
+	}
+
+	/**
+	 * @return Address|null
+	 */
+	public function getReplyTo(): ?Address
+	{
+		return $this->hasHeader('Reply-To') ? Address::create($this->getHeader('Reply-To')->getValue()) : null;
+	}
+
+	/**
+	 * @return Address|null
+	 */
+	public function getReturnPath(): ?Address
+	{
+		return $this->hasHeader('Return-Path') ? Address::create($this->getHeader('Return-Path')->getValue()) : null;
+	}
+
+	/**
+	 * Returns the priority as an integer parsed from the header,
+	 * where 1 is the highest and 5 is the lowest. Default is 3.
+	 *
+	 * @return int
+	 */
+	public function getPriority(): int
+	{
+		if ($this->hasHeader('X-Priority'))
+		{
+			return array_search($this->getHeader('X-Priority')->getValue(), self::PRIORITIES, true) ?: 3;
+		}
+
+		return 3;
+	}
+
+	/**
+	 * @return Time|null
+	 */
+	public function getDate(): ?Time
+	{
+		return $this->hasHeader('Date') ? Time::parse($this->getHeader('Date')->getValue()) : null;
+	}
+
+	//--------------------------------------------------------------------
+	// Backwards Compatibility
+	//--------------------------------------------------------------------
+
+	/**
+	 * @param string $body
+	 *
+	 * @return $this
+	 */
+	public function setMessage($body)
+	{
+		return $this->body(rtrim(str_replace("\r", '', $body)));
+	}
+
+	/**
+	 * Magic method to allow CI3-style methods (like "setReplyTo()") to
+	 * forward to their new equivalent.
+	 *
+	 * @param string $name
+	 * @param array $arguments
+	 *
+	 * @return mixed
+	 */
+	public function __call(string $name, array $arguments)
+	{
+		if (strpos($name, 'set') === 0 && method_exists($this, $method = lcfirst(substr($name, 3))))
+		{
+			return $this->$method(...$arguments);
+		}
+
+		throw new BadMethodCallException("Method {$name} does not exist");
+	}
+}
diff --git a/system/Mailer/MailerInterface.php b/system/Mailer/MailerInterface.php
index d05e21508407..168e2684a657 100644
--- a/system/Mailer/MailerInterface.php
+++ b/system/Mailer/MailerInterface.php
@@ -42,13 +42,11 @@
 interface MailerInterface
 {
 	/**
-	 * Send a Message
+	 * Send an Email
 	 *
-	 * @param Message $message    The email to send
-	 * @param boolean $autoClear  Should old session data be destroyed?
-	 * @param boolean $reallySend Should the message really be sent? or everything but that
+	 * @param Email $email
 	 */
-	public function send(Message $message, bool $autoClear = true, bool $reallySend = true);
+	public function send(Email $email);
 
 	/**
 	 * Which protocol is this a handler for?
diff --git a/tests/system/Mailer/AddressTest.php b/tests/system/Mailer/AddressTest.php
new file mode 100644
index 000000000000..4e13acf53001
--- /dev/null
+++ b/tests/system/Mailer/AddressTest.php
@@ -0,0 +1,137 @@
+<?php
+
+namespace CodeIgniter\Mailer;
+
+use CodeIgniter\Test\CIUnitTestCase;
+
+class AddressTest extends CIUnitTestCase
+{
+	/**
+	 * @dataProvider constructorProvider
+	 */
+	public function testConstructor(string $email, ?string $emailResult, ?string $name, ?string $nameResult)
+	{
+		if (is_null($emailResult))
+		{
+			$this->expectException('InvalidArgumentException');
+			$this->expectExceptionMessage(lang('Mailer.invalidAddress', [$email]));
+		}
+
+		$address = new Address($email, $name);
+
+		$this->assertSame($emailResult, $address->getEmail());
+		$this->assertSame($nameResult, $address->getName());
+	}
+
+	public function constructorProvider(): array
+	{
+		return [
+			'justEmail' => [
+				'leia@alderaan.org',
+				'leia@alderaan.org',
+				null,
+				null,
+			],
+			'emailSpaces' => [
+				' leia@alderaan.org ',
+				'leia@alderaan.org',
+				null,
+				null,
+			],
+			'withName' => [
+				'leia@alderaan.org',
+				'leia@alderaan.org',
+				'Princess Leia',
+				'Princess Leia',
+			],
+			'nameSpaces' => [
+				'leia@alderaan.org',
+				'leia@alderaan.org',
+				' Princess Leia ',
+				'Princess Leia',
+			],
+			'nameQuotes' => [
+				'leia@alderaan.org',
+				'leia@alderaan.org',
+				'"Princess Leia"',
+				'Princess Leia',
+			],
+			'emptyEmail' => [
+				'',
+				null,
+				null,
+				null,
+			],
+			'invalidEmail' => [
+				'leia@alderaan',
+				null,
+				'Princess Leia',
+				'Princess Leia',
+			],
+			'illegalEmail' => [
+				'le ia@alderaan.org',
+				null,
+				null,
+				null,
+			],
+		];
+	}
+
+	/**
+	 * @dataProvider addressProvider
+	 */
+	public function testCreate($address, ?string $emailResult, ?string $nameResult)
+	{
+		if (is_null($emailResult))
+		{
+			$this->expectException('InvalidArgumentException');
+			$this->expectExceptionMessage(lang('Mailer.invalidAddress', ['']));
+		}
+
+		$address = Address::create($address);
+
+		$this->assertSame($emailResult, $address->getEmail());
+		$this->assertSame($nameResult, $address->getName());
+	}
+
+	public function addressProvider(): array
+	{
+		return [
+			'simple' => [
+				'leia@alderaan.org',
+				'leia@alderaan.org',
+				null,
+			],
+			'simpleSpace' => [
+				' leia@alderaan.org',
+				'leia@alderaan.org',
+				null,
+			],
+			'qualified' => [
+				'Princess Leia <leia@alderaan.org>',
+				'leia@alderaan.org',
+				'Princess Leia',
+			],
+			'qualifiedSpaces' => [
+				' Princess Leia  <leia@alderaan.org>',
+				'leia@alderaan.org',
+				'Princess Leia',
+			],
+			'qualifiedQuotes' => [
+				'"Princess Leia" <leia@alderaan.org>',
+				'leia@alderaan.org',
+				'Princess Leia',
+			],
+			'emptyEmail' => [
+				'',
+				null,
+				null,
+			],
+			'alreadyAddress' => [
+				new Address('leia@alderaan.org'),
+				'leia@alderaan.org',
+				null,
+			],
+		];
+	}
+}
diff --git a/tests/system/Mailer/EmailTest.php b/tests/system/Mailer/EmailTest.php
new file mode 100644
index 000000000000..b718117aa9f0
--- /dev/null
+++ b/tests/system/Mailer/EmailTest.php
@@ -0,0 +1,18 @@
+<?php
+
+namespace CodeIgniter\Mailer;
+
+use CodeIgniter\Test\CIUnitTestCase;
+
+class EmailTest extends CIUnitTestCase
+{
+	public function testConstructorUsesData()
+	{
+		$address = 'leia@alderaan.org';
+		$email   = new Email([
+			'from' => $address,
+		]);
+
+		$this->assertSame($address, (string) $email->getFrom());
+	}
+}

From 26c0d500c6316018d1f3881f3961f03b4793a3be Mon Sep 17 00:00:00 2001
From: MGatner <mgatner@icloud.com>
Date: Tue, 1 Jun 2021 02:19:19 +0000
Subject: [PATCH 3/8] Implement config, discovery, & init

---
 app/Config/Mailer.php                        |   18 +-
 system/Config/Services.php                   |   36 +-
 system/Language/en/Mailer.php                |   55 +-
 system/Mailer/Address.php                    |    6 +-
 system/Mailer/Email.php                      |   17 +-
 system/Mailer/Exceptions/MailerException.php |   26 +-
 system/Mailer/Handlers/BaseHandler.php       |    9 +-
 system/Mailer/Handlers/DummyHandler.php      |   35 +
 system/Mailer/Handlers/MailHandler.php       |    8 +-
 system/Mailer/Handlers/SMTPHandler.php       |    6 +-
 system/Mailer/Handlers/SendmailHandler.php   |    6 +-
 system/Mailer/MailerInterface.php            |   51 +-
 system/Mailer/Message.php                    | 1220 ------------------
 13 files changed, 146 insertions(+), 1347 deletions(-)
 create mode 100644 system/Mailer/Handlers/DummyHandler.php
 delete mode 100644 system/Mailer/Message.php

diff --git a/app/Config/Mailer.php b/app/Config/Mailer.php
index 2e0ff0fdb4a0..93f223f2116a 100644
--- a/app/Config/Mailer.php
+++ b/app/Config/Mailer.php
@@ -5,17 +5,21 @@
 class Mailer
 {
 	/**
-	 * Default "from" address.
+	 * Default values to use for every email.
+	 * Valid keys:
+	 * - body, subject, from, to, cc, bcc, replyTo, returnPath, priority, date
 	 *
-	 * @var string|null
+	 * @see \CodeIgniter\Mailer\Email::__construct()
+	 *
+	 * @var array<string,mixed>
 	 */
-	public $from;
+	public $defaults = [];
 
 	/**
-	 * Default email priority.
-	 * 1 = highest, 3 = normal, 5 = lowest
+	 * The name of the preferred handler to use.
+	 * Testing disables mail by default.
 	 *
-	 * @var integer
+	 * @var string
 	 */
-	public $priority = 3;
+	public $handler = ENVIRONMENT === 'testing' ? 'dummy' : 'mail';
 }
diff --git a/system/Config/Services.php b/system/Config/Services.php
index ee3e07d0747e..102af71fd800 100644
--- a/system/Config/Services.php
+++ b/system/Config/Services.php
@@ -42,6 +42,8 @@
 use CodeIgniter\Images\Handlers\BaseHandler;
 use CodeIgniter\Language\Language;
 use CodeIgniter\Log\Logger;
+use CodeIgniter\Mailer\Exceptions\MailerException;
+use CodeIgniter\Mailer\MailerInterface;
 use CodeIgniter\Pager\Pager;
 use CodeIgniter\Router\RouteCollection;
 use CodeIgniter\Router\RouteCollectionInterface;
@@ -386,36 +388,38 @@ public static function logger(bool $getShared = true)
     //--------------------------------------------------------------------
 
     /**
-     * The Mailer class lets you send composed messages via mail, sendmail, SMTP.
+     * The Mailer class sends emails from any of the available protocol handlers.
      *
      * @param MailerConfig|null $config
      * @param boolean $getShared
      *
-     * @return \CodeIgniter\Mailer\MailerInterface
+     * @return MailerInterface
+     *
+     * @throws MailerException
      */
-    public static function mailer(MailerConfig $config = null, bool $getShared = true)
+    public static function mailer(MailerConfig $config = null, bool $getShared = true): MailerInterface
     {
         if ($getShared)
         {
             return static::getSharedInstance('mailer', $config);
         }
 
-        if (empty($config))
-        {
-            $config = new MailerConfig();
-        }
-
-        $protocolMap = [
-            'mail'     => 'MailHandler',
-            'sendmail' => 'SendmailHandler',
-            'smtp'     => 'SMTPHandler',
+        // Factories to load the configured default handler 
+        $config  = $config ?? config('Mailer');
+        $handler = ucfirst($config->handler) . 'Handler';
+        $options = [
+            'path'       => 'Mailer/Handlers',
+            'instanceOf' => MailerInterface::class,
+            'getShared'  => false, // allows Services to handle sharing
+            'preferApp'  => true,
         ];
 
-        $handler   = '\\CodeIgniter\\Mailer\\Handlers\\' . ($protocolMap[$config->protocol ?? 'mail'] );
-        $mailer = new $handler($config);
-        $mailer->setLogger(static::logger(true));
+        if ($result = Factories::mailer($handler, $options, $config))
+        {
+            return $result;
+        }
 
-        return $mailer;
+        throw MailerException::forHandlerNotFound();
     }
 
     //--------------------------------------------------------------------
diff --git a/system/Language/en/Mailer.php b/system/Language/en/Mailer.php
index b5c49c818c7d..4bbb3d386f4e 100644
--- a/system/Language/en/Mailer.php
+++ b/system/Language/en/Mailer.php
@@ -1,36 +1,35 @@
 <?php
+
 /**
- * Messenger language strings.
+ * This file is part of the CodeIgniter 4 framework.
  *
- * @package    CodeIgniter
- * @author     CodeIgniter Dev Team
- * @copyright  2019-2020 CodeIgniter Foundation
- * @license    https://opensource.org/licenses/MIT	MIT License
- * @link       https://codeigniter.com
- * @since      Version 3.0.0
- * @filesource
+ * (c) CodeIgniter Foundation <admin@codeigniter.com>
  *
- * @codeCoverageIgnore
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
  */
 
 return [
-   'mustBeArray'          => 'The email validation method must be passed an array.',
-   'invalidAddress'       => 'Invalid email address: {0}',
-   'attachmentMissing'    => 'Unable to locate the following email attachment: {0}',
-   'attachmentUnreadable' => 'Unable to open this attachment: {0}',
-   'noFrom'               => 'Cannot send mail with no "From" header.',
-   'noRecipients'         => 'You must include recipients: To, Cc, or Bcc',
-   'sendFailurePHPMail'   => 'Unable to send email using PHP mail(). Your server might not be configured to send mail using this method.',
-   'sendFailureSendmail'  => 'Unable to send email using PHP Sendmail. Your server might not be configured to send mail using this method.',
-   'sendFailureSmtp'      => 'Unable to send email using PHP SMTP. Your server might not be configured to send mail using this method.',
-   'sent'                 => 'Your message has been successfully sent using the following protocol: {0}',
-   'noSocket'             => 'Unable to open a socket to Sendmail. Please check settings.',
-   'noHostname'           => 'You did not specify a SMTP hostname.',
-   'SMTPError'            => 'The following SMTP error was encountered: {0}',
-   'noSMTPAuth'           => 'Error: You must assign a SMTP username and password.',
-   'failedSMTPLogin'      => 'Failed to send AUTH LOGIN command. Error: {0}',
-   'SMTPAuthUsername'     => 'Failed to authenticate username. Error: {0}',
-   'SMTPAuthPassword'     => 'Failed to authenticate password. Error: {0}',
-   'SMTPDataFailure'      => 'Unable to send data: {0}',
-   'exitStatus'           => 'Exit status code: {0}',
+	'handlerNotFound' => 'Mailer config has an invalid or missing handler.',
+	'invalidAddress'  => 'Invalid email address: {0}',
+/*
+	'mustBeArray'          => 'The email validation method must be passed an array.',
+	'attachmentMissing'    => 'Unable to locate the following email attachment: {0}',
+	'attachmentUnreadable' => 'Unable to open this attachment: {0}',
+	'noFrom'               => 'Cannot send mail with no "From" header.',
+	'noRecipients'         => 'You must include recipients: To, Cc, or Bcc',
+	'sendFailurePHPMail'   => 'Unable to send email using PHP mail(). Your server might not be configured to send mail using this method.',
+	'sendFailureSendmail'  => 'Unable to send email using PHP Sendmail. Your server might not be configured to send mail using this method.',
+	'sendFailureSmtp'      => 'Unable to send email using PHP SMTP. Your server might not be configured to send mail using this method.',
+	'sent'                 => 'Your message has been successfully sent using the following protocol: {0}',
+	'noSocket'             => 'Unable to open a socket to Sendmail. Please check settings.',
+	'noHostname'           => 'You did not specify a SMTP hostname.',
+	'SMTPError'            => 'The following SMTP error was encountered: {0}',
+	'noSMTPAuth'           => 'Error: You must assign a SMTP username and password.',
+	'failedSMTPLogin'      => 'Failed to send AUTH LOGIN command. Error: {0}',
+	'SMTPAuthUsername'     => 'Failed to authenticate username. Error: {0}',
+	'SMTPAuthPassword'     => 'Failed to authenticate password. Error: {0}',
+	'SMTPDataFailure'      => 'Unable to send data: {0}',
+	'exitStatus'           => 'Exit status code: {0}',
+*/
 ];
diff --git a/system/Mailer/Address.php b/system/Mailer/Address.php
index 2a2273080c77..25c78714f9af 100644
--- a/system/Mailer/Address.php
+++ b/system/Mailer/Address.php
@@ -11,7 +11,7 @@
 
 namespace CodeIgniter\Mailer;
 
-use InvalidArgumentException;
+use CodeIgniter\Mailer\Exceptions\MailerException;
 
 class Address
 {
@@ -102,6 +102,8 @@ final public static function merge(string $email, string $name = null): string
 	 *
 	 * @param string $email
 	 * @param string|null $name
+	 *
+	 * @throws MailerException
 	 */
 	final public function __construct(string $email, string $name = null)
 	{
@@ -109,7 +111,7 @@ final public function __construct(string $email, string $name = null)
 
 		if (! service('validation')->check($this->email, 'required|valid_email'))
 		{
-			throw new InvalidArgumentException(lang('Mailer.invalidAddress', [$email]));
+			throw MailerException::forInvalidAddress($email);
 		}
 
 		$this->name  = isset($name) ? trim($name, ' \'"') : null;
diff --git a/system/Mailer/Email.php b/system/Mailer/Email.php
index 689e57707106..a338577ae9d6 100644
--- a/system/Mailer/Email.php
+++ b/system/Mailer/Email.php
@@ -39,6 +39,9 @@ class Email extends Message
 	 */
 	public function __construct(array $data = [])
 	{
+		// Start with config defaults but prioritize any overrides
+		$data = array_merge(config('Mailer')->defaults, $data);
+
 		// Check for any keys that match our setters
 		foreach ([
 			'body',
@@ -58,18 +61,6 @@ public function __construct(array $data = [])
 				$this->$method($data[$method]);
 			}
 		}
-/*
-		// Check for missing defaults and set the config values
-		$config = config('Mailer');
-		if (! array_key_exists('from', $data) && isset($config->from))
-		{
-			$this->from(Address::create($config->from));
-		}
-		if (! array_key_exists('priority', $data))
-		{
-			$this->priority($config->priority);
-		}
-*/
 	}
 
 	//--------------------------------------------------------------------
@@ -297,6 +288,8 @@ public function setMessage($body)
 	 * @param array $arguments
 	 *
 	 * @return mixed
+	 *
+	 * @throws BadMethodCallException
 	 */
 	public function __call(string $name, array $arguments)
 	{
diff --git a/system/Mailer/Exceptions/MailerException.php b/system/Mailer/Exceptions/MailerException.php
index eb1a232aab17..ed65361a2c44 100644
--- a/system/Mailer/Exceptions/MailerException.php
+++ b/system/Mailer/Exceptions/MailerException.php
@@ -15,6 +15,27 @@
 
 class MailerException extends FrameworkException
 {
+	/**
+	 * Thrown when specified handler was not found.
+	 *
+	 * @return static
+	 */
+	public static function forHandlerNotFound()
+	{
+		return new static(lang('Mailer.handlerNotFound'));
+	}
+
+	/**
+	 * Thrown when an email address fails validation
+	 *
+	 * @return static
+	 */
+	public static function forInvalidAddress(string $value = null)
+	{
+		return new static(lang('Mailer.invalidAddress', [$value]));
+	}
+
+/*
 	public static function forAttachmentMissing(string $file = null)
 	{
 		return new static(lang('Mailer.attachmentMissing', [$file]));
@@ -30,10 +51,6 @@ public static function forMustBeArray()
 		return new static(lang('Mailer.mustBeArray', []));
 	}
 
-	public static function forInvalidAddress(string $value = null)
-	{
-		return new static(lang('Mailer.invalidAddress', [$value]));
-	}
 
 	public static function forInvalidProtocol(string $value = null)
 	{
@@ -94,4 +111,5 @@ public static function forSMTPDataFailure(string $data = '?')
 	{
 		return new static(lang('Mailer.SMTPDataFailure', [$data]));
 	}
+*/
 }
diff --git a/system/Mailer/Handlers/BaseHandler.php b/system/Mailer/Handlers/BaseHandler.php
index 8e25f038471e..3c56baea7975 100644
--- a/system/Mailer/Handlers/BaseHandler.php
+++ b/system/Mailer/Handlers/BaseHandler.php
@@ -39,9 +39,9 @@
  * @filesource
  */
 
+use CodeIgniter\Mailer\Email;
 use CodeIgniter\Mailer\Exceptions\MailerException;
 use CodeIgniter\Mailer\MailerInterface;
-use CodeIgniter\Mailer\Message;
 use Config\Mimes;
 use Psr\Log\LoggerAwareTrait;
 use Psr\Log\LoggerInterface;
@@ -835,14 +835,13 @@ protected function prepQuotedPrintable($str)
 	//--------------------------------------------------------------------
 
 	/**
-	 * Send a Message
+	 * Sends an Email
 	 *
-	 * @param boolean $autoClear
-	 * @param boolean $reallySend
+	 * @param Email $email
 	 *
 	 * @return boolean
 	 */
-	public function send(Message $message, bool $autoClear = true, bool $reallySend = true)
+	public function send(Email $email)
 	{
 		if (! isset($this->headers['From']) && ! empty($this->fromEmail))
 		{
diff --git a/system/Mailer/Handlers/DummyHandler.php b/system/Mailer/Handlers/DummyHandler.php
new file mode 100644
index 000000000000..e5fb348ea6bd
--- /dev/null
+++ b/system/Mailer/Handlers/DummyHandler.php
@@ -0,0 +1,35 @@
+<?php
+
+/**
+ * This file is part of the CodeIgniter 4 framework.
+ *
+ * (c) CodeIgniter Foundation <admin@codeigniter.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace CodeIgniter\Mailer\Handlers;
+
+use CodeIgniter\Mailer\Email;
+use CodeIgniter\Mailer\MailerInterface;
+use Config\Mailer;
+
+class DummyHandler implements MailerInterface
+{
+	/**
+	 * @param Mailer $config
+	 */
+	public function __construct(Mailer $config)
+	{
+	}
+
+	/**
+	 * Does not send an Email
+	 *
+	 * @param Email $email
+	 */
+	public function send(Email $email)
+	{
+	}
+}
diff --git a/system/Mailer/Handlers/MailHandler.php b/system/Mailer/Handlers/MailHandler.php
index 3dced67d758b..1a9421b8772d 100644
--- a/system/Mailer/Handlers/MailHandler.php
+++ b/system/Mailer/Handlers/MailHandler.php
@@ -38,7 +38,7 @@
  * @filesource
  */
 
-use CodeIgniter\Mailer\Message;
+use CodeIgniter\Mailer\Email;
 use CodeIgniter\Mailer\Exceptions\MailerException;
 use Config\Mimes;
 use Psr\Log\LoggerAwareTrait;
@@ -899,13 +899,13 @@ protected function prepQEncoding($str)
 	//--------------------------------------------------------------------
 
 	/**
-	 * Send a Message
+	 * Send an Email
 	 *
-	 * @param boolean $autoClear
+	 * @param Email $email
 	 *
 	 * @return boolean
 	 */
-	public function send(Message $message, bool $autoClear = true, bool $reallySend = true)
+	public function send(Email $email)
 	{
 		if (! isset($this->headers['From']) && ! empty($this->fromEmail))
 		{
diff --git a/system/Mailer/Handlers/SMTPHandler.php b/system/Mailer/Handlers/SMTPHandler.php
index 9e7248fbd2f1..eaeefa52d5de 100644
--- a/system/Mailer/Handlers/SMTPHandler.php
+++ b/system/Mailer/Handlers/SMTPHandler.php
@@ -38,7 +38,7 @@
  * @filesource
  */
 
-use CodeIgniter\Mailer\Message;
+use CodeIgniter\Mailer\Email;
 use CodeIgniter\Mailer\Exceptions\MailerException;
 use Config\Mimes;
 use Psr\Log\LoggerAwareTrait;
@@ -905,11 +905,11 @@ protected function prepQEncoding($str)
 	/**
 	 * Send the Message
 	 *
-	 * @param boolean $autoClear
+	 * @param Email $email
 	 *
 	 * @return boolean
 	 */
-	public function send(Message $message, bool $autoClear = true, bool $reallySend = true)
+	public function send(Email $email)
 	{
 		if (! isset($this->headers['From']) && ! empty($this->fromEmail))
 		{
diff --git a/system/Mailer/Handlers/SendmailHandler.php b/system/Mailer/Handlers/SendmailHandler.php
index 9194552a41c0..5e339579622e 100644
--- a/system/Mailer/Handlers/SendmailHandler.php
+++ b/system/Mailer/Handlers/SendmailHandler.php
@@ -38,7 +38,7 @@
  * @filesource
  */
 
-use CodeIgniter\Mailer\Message;
+use CodeIgniter\Mailer\Email;
 use CodeIgniter\Mailer\Exceptions\MailerException;
 use Config\Mimes;
 use Psr\Log\LoggerAwareTrait;
@@ -905,11 +905,11 @@ protected function prepQEncoding($str)
 	/**
 	 * Send a Message
 	 *
-	 * @param boolean $autoClear
+	 * @param Email $email
 	 *
 	 * @return boolean
 	 */
-	public function send(Message $message, bool $autoClear = true, bool $reallySend = true)
+	public function send(Email $email)
 	{
 		if (! isset($this->headers['From']) && ! empty($this->fromEmail))
 		{
diff --git a/system/Mailer/MailerInterface.php b/system/Mailer/MailerInterface.php
index 168e2684a657..ea05f5a9990c 100644
--- a/system/Mailer/MailerInterface.php
+++ b/system/Mailer/MailerInterface.php
@@ -1,57 +1,22 @@
-<?php namespace CodeIgniter\Mailer;
+<?php
 
 /**
- * CodeIgniter
+ * This file is part of the CodeIgniter 4 framework.
  *
- * An open source application development framework for PHP
+ * (c) CodeIgniter Foundation <admin@codeigniter.com>
  *
- * This content is released under the MIT License (MIT)
- *
- * Copyright (c) 2014-2018 British Columbia Institute of Technology
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in
- * all copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
- * THE SOFTWARE.
- *
- * @package    CodeIgniter
- * @author     CodeIgniter Dev Team
- * @copyright  2014-2018 British Columbia Institute of Technology (https://bcit.ca/)
- * @license    https://opensource.org/licenses/MIT	MIT License
- * @link       https://codeigniter.com
- * @since      Version 3.0.0
- * @filesource
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
  */
 
-/**
- * Expected behavior of a Mailer handler used with CodeIgniter.
- */
+namespace CodeIgniter\Mailer;
+
 interface MailerInterface
 {
 	/**
-	 * Send an Email
+	 * Sends an Email
 	 *
 	 * @param Email $email
 	 */
 	public function send(Email $email);
-
-	/**
-	 * Which protocol is this a handler for?
-	 */
-	public function getProtocol(): string;
-
-	//--------------------------------------------------------------------
 }
diff --git a/system/Mailer/Message.php b/system/Mailer/Message.php
deleted file mode 100644
index a29cd47181bf..000000000000
--- a/system/Mailer/Message.php
+++ /dev/null
@@ -1,1220 +0,0 @@
-<?php namespace CodeIgniter\Mailer;
-
-/**
- * CodeIgniter
- *
- * An open source application development framework for PHP
- *
- * This content is released under the MIT License (MIT)
- *
- * Copyright (c) 2014 - 2019, British Columbia Institute of Technology
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in
- * all copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
- * THE SOFTWARE.
- *
- * @package    CodeIgniter
- * @author     EllisLab Dev Team
- * @copyright  Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright  Copyright (c) 2014 - 2020, British Columbia Institute of Technology (http://bcit.ca/)
- * @license    http://opensource.org/licenses/MIT    MIT License
- * @link       https://codeigniter.com
- * @since      Version 1.0.0
- * @filesource
- */
-
-use CodeIgniter\Config\Services;
-use CodeIgniter\Mailer\Exceptions\MailerException;
-use Config\Mailer as MailerConfig;
-use Config\Mimes;
-use Psr\Log\LoggerAwareTrait;
-
-/**
- * CodeIgniter Message Class
- *
- * Object model for a message to be sent using Mail, Sendmail, or SMTP.
- */
-class Message
-{
-	use LoggerAwareTrait;
-
-	/**
-	 * @var string
-	 */
-	public $fromEmail;
-
-	/**
-	 * @var string
-	 */
-	public $fromName;
-
-	/**
-	 * Whether to apply word-wrapping to the message body.
-	 *
-	 * @var boolean
-	 */
-	public $wordWrap = true;
-
-	/**
-	 * Number of characters to wrap at.
-	 *
-	 * @see self::$wordWrap
-	 * @var integer
-	 */
-	public $wrapChars = 76;
-
-	/**
-	 * Message format.
-	 *
-	 * @var string 'text' or 'html'
-	 */
-	public $mailType = 'text';
-
-	/**
-	 * Character set (default: utf-8)
-	 *
-	 * @var string
-	 */
-	public $charset = 'utf-8';
-
-	/**
-	 * Alternative message (for HTML messages only)
-	 *
-	 * @var string
-	 */
-	public $altMessage = '';
-
-	/**
-	 * Whether to validate e-mail addresses.
-	 *
-	 * @var boolean
-	 */
-	public $validate = true;
-
-	/**
-	 * X-Priority header value.
-	 *
-	 * @var integer 1-5
-	 */
-	public $priority = 3;   // Default priority (1 - 5)
-
-	/**
-	 * Newline character sequence.
-	 * Use "\r\n" to comply with RFC 822.
-	 *
-	 * @link http://www.ietf.org/rfc/rfc822.txt
-	 * @var  string "\r\n" or "\n"
-	 */
-	public $newline = "\n";   // Default newline. "\r\n" or "\n" (Use "\r\n" to comply with RFC 822)
-
-	/**
-	 * CRLF character sequence
-	 *
-	 * RFC 2045 specifies that for 'quoted-printable' encoding,
-	 * "\r\n" must be used. However, it appears that some servers
-	 * (even on the receiving end) don't handle it properly and
-	 * switching to "\n", while improper, is the only solution
-	 * that seems to work for all environments.
-	 *
-	 * @link http://www.ietf.org/rfc/rfc822.txt
-	 * @var  string
-	 */
-	public $CRLF = "\n";
-
-	/**
-	 * Whether to use Delivery Status Notification.
-	 *
-	 * @var boolean
-	 */
-	public $DSN = false;
-
-	/**
-	 * Whether to send multipart alternatives.
-	 * Yahoo! doesn't seem to like these.
-	 *
-	 * @var boolean
-	 */
-	public $sendMultipart = true;
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Subject header
-	 *
-	 * @var string
-	 */
-	protected $subject = '';
-
-	/**
-	 * Message body
-	 *
-	 * @var string
-	 */
-	protected $body = '';
-
-	/**
-	 * Final message body to be sent.
-	 *
-	 * @var string
-	 */
-	protected $finalBody = '';
-
-	/**
-	 * Final headers to send
-	 *
-	 * @var string
-	 */
-	protected $headerStr = '';
-
-	/**
-	 * Mail encoding
-	 *
-	 * @var string '8bit' or '7bit'
-	 */
-	protected $encoding = '8bit';
-
-	/**
-	 * Whether to send a Reply-To header
-	 *
-	 * @var boolean
-	 */
-	protected $replyToFlag = false;
-
-	/**
-	 * Debug messages
-	 *
-	 * @see self::printDebugger()
-	 * @var array
-	 */
-	protected $debugMessage = [];
-
-	/**
-	 * Recipients
-	 *
-	 * @var array
-	 */
-	protected $recipients = [];
-
-	/**
-	 * CC Recipients
-	 *
-	 * @var array
-	 */
-	protected $CCArray = [];
-
-	/**
-	 * BCC Recipients
-	 *
-	 * @var array
-	 */
-	protected $BCCArray = [];
-
-	/**
-	 * Message headers
-	 *
-	 * @var array
-	 */
-	protected $headers = [];
-
-	/**
-	 * Attachment data
-	 *
-	 * @var array
-	 */
-	protected $attachments = [];
-
-	/**
-	 * Which protocol are we using?
-	 *
-	 * @var string
-	 */
-	protected $protocol = 'mail';
-
-	/**
-	 * Valid $protocol values
-	 *
-	 * @see self::$protocol
-	 * @var array
-	 */
-	protected $protocols = [
-		'mail',
-		'sendmail',
-		'smtp',
-	];
-
-	/**
-	 * Base charsets
-	 *
-	 * Character sets valid for 7-bit encoding,
-	 * excluding language suffix.
-	 *
-	 * @var array
-	 */
-	protected $baseCharsets = [
-		'us-ascii',
-		'iso-2022-',
-	];
-
-	/**
-	 * Bit depths
-	 *
-	 * Valid mail encodings
-	 *
-	 * @see self::$encoding
-	 * @var array
-	 */
-	protected $bitDepths = [
-		'7bit',
-		'8bit',
-	];
-
-	/**
-	 * $priority translations
-	 *
-	 * Actual values to send with the X-Priority header
-	 *
-	 * @var array
-	 */
-	protected $priorities = [
-		1 => '1 (Highest)',
-		2 => '2 (High)',
-		3 => '3 (Normal)',
-		4 => '4 (Low)',
-		5 => '5 (Lowest)',
-	];
-
-	/**
-	 * Logger instance to record error messages and awarnings.
-	 *
-	 * @var \Psr\Log\LoggerInterface
-	 */
-	protected $logger;
-
-	/**
-	 * Mailer that this message is bound to
-	 *
-	 * @var \CodeIgniter\Mailer\MailerInterface
-	 */
-	protected $handler;
-
-	/**
-	 * Config settings, used if protocol changed.
-	 *
-	 * @var MailerConfig
-	 */
-	protected $config = null;
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Constructor - Sets Preferences
-	 *
-	 * The constructor can be passed an array of config values
-	 *
-	 * @param array|null $config
-	 */
-	public function __construct($config = null)
-	{
-		if ($config === null)
-		{
-			$config       = new \Config\Mailer();
-			$this->config = $config;
-		}
-		else if (is_array($config))
-		{
-			$mergedConfig = new \Config\Mailer();
-			foreach ($config as $key => $value)
-			{
-				$mergedConfig->$key = $value;
-			}
-			$this->config = $mergedConfig;
-		}
-		$this->initialize($config);
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Initialize preferences
-	 *
-	 * @param array|\Config\Mailer $config
-	 *
-	 * @return $this
-	 */
-	public function initialize($config)
-	{
-		$this->clear();
-		if ($config instanceof \Config\Mailer)
-		{
-			$config = get_object_vars($config);
-		}
-
-		foreach (get_class_vars(get_class($this)) as $key => $value)
-		{
-			if (property_exists($this, $key) && isset($config[$key]))
-			{
-				$method = 'set' . ucfirst($key);
-
-				if (method_exists($this, $method))
-				{
-					$this->$method($config[$key]);
-				}
-				else
-				{
-					$this->$key = $config[$key];
-				}
-			}
-		}
-
-		$this->charset = strtoupper($this->charset);
-		$this->handler = Services::mailer($config);
-
-		return $this;
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Set the protocol to use.
-	 * If valid, get an appropriate handler for it.
-	 *
-	 * @param string $protocol
-	 *
-	 * @returns $this
-	 */
-	public function setProtocol(string $protocol = 'mail')
-	{
-		if (! in_array($protocol, $this->protocols))
-		{
-			throw MailerException::forInvalidProtocol($protocol);
-		}
-
-		$this->protocol         = $protocol;
-		$this->config->protocol = $protocol; // update config too
-		$this->handler          = Services::mailer($this->config, false);
-
-		return $this;
-	}
-
-	/**
-	 * Get the protocol our handler is using.
-	 * Note: the protocol property here is only the requested one.
-	 *
-	 * @return string
-	 */
-	public function getProtocol(): string
-	{
-		return $this->handler->getProtocol();
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Initialize the Data
-	 *
-	 * @param boolean $clearAttachments
-	 *
-	 * @return $this
-	 */
-	public function clear($clearAttachments = false)
-	{
-		$this->subject     = '';
-		$this->body        = '';
-		$this->finalBody   = '';
-		$this->headerStr   = '';
-		$this->replyToFlag = false;
-		$this->recipients  = [];
-		$this->CCArray     = [];
-		$this->BCCArray    = [];
-		$this->headers     = [];
-
-		$this->setHeader('Date', $this->setDate());
-
-		if ($clearAttachments !== false)
-		{
-			$this->attachments = [];
-		}
-
-		return $this;
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Set FROM
-	 *
-	 * @param string      $from
-	 * @param string      $name
-	 * @param string|null $returnPath Return-Path
-	 *
-	 * @return $this
-	 */
-	public function setFrom($from, $name = '', $returnPath = null)
-	{
-		if (preg_match('/\<(.*)\>/', $from, $match))
-		{
-			$from = $match[1];
-		}
-
-		if ($this->validate)
-		{
-			$this->validateEmail($from);
-			if ($returnPath)
-			{
-				$this->validateEmail($returnPath);
-			}
-		}
-
-		// prepare the display name
-		if ($name !== '')
-		{
-			// only use Q encoding if there are characters that would require it
-			if (! preg_match('/[\200-\377]/', $name))
-			{
-				// add slashes for non-printing characters, slashes, and double quotes, and surround it in double quotes
-				$name = '"' . addcslashes($name, "\0..\37\177'\"\\") . '"';
-			}
-			else
-			{
-				$name = $this->prepQEncoding($name);
-			}
-		}
-
-		$this->setHeader('From', $name . ' <' . $from . '>');
-		isset($returnPath) || $returnPath = $from;
-		$this->setHeader('Return-Path', '<' . $returnPath . '>');
-
-		return $this;
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Prep Q Encoding
-	 *
-	 * Performs "Q Encoding" on a string for use in headers.
-	 * It's related but not identical to quoted-printable, so it has its
-	 * own method.
-	 *
-	 * @param string $str
-	 *
-	 * @return string
-	 */
-	protected function prepQEncoding($str)
-	{
-		$str = str_replace(["\r", "\n"], '', $str);
-
-		if ($this->charset === 'UTF-8')
-		{
-			// Note: We used to have mb_encode_mimeheader() as the first choice
-			//       here, but it turned out to be buggy and unreliable. DO NOT
-			//       re-add it! -- Narf
-			if (extension_loaded('iconv'))
-			{
-				$output = @iconv_mime_encode(
-								'', $str, [
-									'scheme'           => 'Q',
-									'line-length'      => 76,
-									'input-charset'    => $this->charset,
-									'output-charset'   => $this->charset,
-									'line-break-chars' => $this->CRLF,
-								]);
-
-				// There are reports that iconv_mime_encode() might fail and return FALSE
-				if ($output !== false)
-				{
-					// iconv_mime_encode() will always put a header field name.
-					// We've passed it an empty one, but it still prepends our
-					// encoded string with ': ', so we need to strip it.
-					return mb_substr($output, 2);
-				}
-
-				$chars = iconv_strlen($str, 'UTF-8');
-			}
-			elseif (extension_loaded('mbstring'))
-			{
-				$chars = mb_strlen($str, 'UTF-8');
-			}
-		}
-
-		// We might already have this set for UTF-8
-		isset($chars) || $chars = mb_strlen($str);
-
-		$output = '=?' . $this->charset . '?Q?';
-		for ($i = 0, $length = mb_strlen($output); $i < $chars; $i ++)
-		{
-			$chr = ($this->charset === 'UTF-8' && ICONV_ENABLED === true) ? '=' . implode('=', str_split(strtoupper(bin2hex(iconv_substr($str, $i, 1, $this->charset))), 2)) : '=' . strtoupper(bin2hex($str[$i]));
-
-			// RFC 2045 sets a limit of 76 characters per line.
-			// We'll append ?= to the end of each line though.
-			if ($length + ($l = mb_strlen($chr)) > 74)
-			{
-				$output .= '?=' . $this->CRLF // EOL
-						. ' =?' . $this->charset . '?Q?' . $chr; // New line
-				$length  = 6 + mb_strlen($this->charset) + $l; // Reset the length for the new line
-			}
-			else
-			{
-				$output .= $chr;
-				$length += $l;
-			}
-		}
-
-		// End the header
-		return $output . '?=';
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Set Reply-to
-	 *
-	 * @param string $replyto
-	 * @param string $name
-	 *
-	 * @return $this
-	 */
-	public function setReplyTo($replyto, $name = '')
-	{
-		if (preg_match('/\<(.*)\>/', $replyto, $match))
-		{
-			$replyto = $match[1];
-		}
-
-		if ($this->validate)
-		{
-			$this->validateEmail($this->stringToArray($replyto));
-		}
-
-		if ($name !== '')
-		{
-			// only use Q encoding if there are characters that would require it
-			if (! preg_match('/[\200-\377]/', $name))
-			{
-				// add slashes for non-printing characters, slashes, and double quotes, and surround it in double quotes
-				$name = '"' . addcslashes($name, "\0..\37\177'\"\\") . '"';
-			}
-			else
-			{
-				$name = $this->prepQEncoding($name);
-			}
-		}
-
-		$this->setHeader('Reply-To', $name . ' <' . $replyto . '>');
-		$this->replyToFlag = true;
-
-		return $this;
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Set Recipients
-	 *
-	 * @param string|array $to One or more recipients
-	 *
-	 * @return $this
-	 */
-	public function setTo($to)
-	{
-		$to = $this->stringToArray($to);
-		$to = $this->cleanEmail($to);
-
-		if ($this->validate)
-		{
-			$this->validateEmail($to);
-		}
-
-		if ($this->handler->getProtocol() !== 'mail')
-		{
-			$this->setHeader('To', implode(', ', $to));
-		}
-
-		$this->recipients = $to;
-
-		return $this;
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Set CC
-	 *
-	 * @param string|array $cc
-	 *
-	 * @return $this
-	 */
-	public function setCC($cc)
-	{
-		$cc = $this->cleanEmail($this->stringToArray($cc));
-
-		if ($this->validate)
-		{
-			$this->validateEmail($cc);
-		}
-
-		$this->setHeader('Cc', implode(', ', $cc));
-
-		//      if ($this->handler->getProtocol() === 'smtp')
-		//      {
-		$this->CCArray = $cc;
-		//      }
-
-		return $this;
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Set BCC
-	 *
-	 * @param string|array $bcc
-	 * @param integer|null $limit
-	 *
-	 * @return $this
-	 */
-	public function setBCC($bcc, int $limit = null)
-	{
-		if ($limit !== null)
-		{
-			$this->BCCBatchMode = true;
-			$this->BCCBatchSize = $limit;
-		}
-
-		$bcc = $this->cleanEmail($this->stringToArray($bcc));
-
-		if ($this->validate)
-		{
-			$this->validateEmail($bcc);
-		}
-
-		//      if ($this->handler->getProtocol() === 'smtp' ||
-		//              if ($this->BCCBatchMode && count($bcc) > $this->BCCBatchSize)
-		//      {
-		$this->BCCArray = $bcc;
-		//      }
-		//      else
-		//      {
-		$this->setHeader('Bcc', implode(', ', $bcc));
-		//      }
-
-		return $this;
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Set Subject
-	 *
-	 * @param string $subject
-	 *
-	 * @return $this
-	 */
-	public function setSubject($subject)
-	{
-		$subject = $this->prepQEncoding($subject);
-		$this->setHeader('Subject', $subject);
-
-		return $this;
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Set Body
-	 *
-	 * @param string $body
-	 *
-	 * @return $this
-	 */
-	public function setMessage($body)
-	{
-		$this->body = rtrim(str_replace("\r", '', $body));
-
-		return $this;
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Assign file attachments
-	 *
-	 * @param string $file        Can be local path, URL or buffered content
-	 * @param string $disposition 'attachment'
-	 * @param string $newName
-	 * @param string $mime        Not-empty if $file is buffered content
-	 *
-	 * @return $this
-	 */
-	public function attach(string $file, string $disposition = '', string $newName = '', string $mime = '')
-	{
-		if ($mime === '')
-		{
-			if (strpos($file, '://') === false && ! is_file($file))
-			{
-				throw MailerException::forAttachmentMissing($file);
-			}
-
-			if (! $fp = @fopen($file, 'rb'))
-			{
-				throw MailerException::forAttachmentUnreadable($file);
-			}
-
-			$fileContent = stream_get_contents($fp);
-			$mime        = $this->mimeTypes(pathinfo($file, PATHINFO_EXTENSION));
-			fclose($fp);
-		}
-		else
-		{
-			$fileContent = & $file; // buffered file
-		}
-
-		// declare names on their own, to make phpcbf happy
-		$namesAttached       = [
-			$file,
-			$newName,
-		];
-		$this->attachments[] = [
-			'name'        => $namesAttached,
-			'disposition' => empty($disposition) ? 'attachment' : $disposition,
-			// Can also be 'inline'  Not sure if it matters
-			'type'        => $mime,
-			'content'     => chunk_split(base64_encode($fileContent)),
-			'multipart'   => 'mixed',
-		];
-
-		return $this;
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Add a Header Item
-	 *
-	 * @param string $header
-	 * @param string $value
-	 *
-	 * @return $this
-	 */
-	public function setHeader($header, $value)
-	{
-		$this->headers[$header] = str_replace(["\n", "\r"], '', $value);
-
-		return $this;
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Convert a String to an Array
-	 *
-	 * @param string $email
-	 *
-	 * @return array
-	 */
-	protected function stringToArray($email)
-	{
-		if (! is_array($email))
-		{
-			return (strpos($email, ',') !== false) ? preg_split('/[\s,]/', $email, -1, PREG_SPLIT_NO_EMPTY) : (array) trim($email);
-		}
-
-		return $email;
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Set Multipart Value
-	 *
-	 * @param string $str
-	 *
-	 * @return $this
-	 */
-	public function setAltMessage($str)
-	{
-		$this->altMessage = (string) $str;
-
-		return $this;
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Set Mailtype
-	 *
-	 * @param string $type
-	 *
-	 * @return $this
-	 */
-	public function setMailType($type = 'text')
-	{
-		$this->mailType = ($type === 'html') ? 'html' : 'text';
-
-		return $this;
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Set Wordwrap
-	 *
-	 * @param boolean $wordWrap
-	 *
-	 * @return $this
-	 */
-	public function setWordWrap($wordWrap = true)
-	{
-		$this->wordWrap = (bool) $wordWrap;
-
-		return $this;
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Set Priority
-	 *
-	 * @param integer $n
-	 *
-	 * @return $this
-	 */
-	public function setPriority($n = 3)
-	{
-		$this->priority = preg_match('/^[1-5]$/', $n) ? (int) $n : 3;
-
-		return $this;
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Set Newline Character
-	 *
-	 * @param string $newline
-	 *
-	 * @return $this
-	 */
-	public function setNewline($newline = "\n")
-	{
-		$this->newline = in_array($newline, ["\n", "\r\n", "\r"]) ? $newline : "\n";
-
-		return $this;
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Set CRLF
-	 *
-	 * @param string $CRLF
-	 *
-	 * @return $this
-	 */
-	public function setCRLF($CRLF = "\n")
-	{
-		$this->CRLF = ($CRLF !== "\n" && $CRLF !== "\r\n" && $CRLF !== "\r") ? "\n" : $CRLF;
-
-		return $this;
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Set RFC 822 Date
-	 *
-	 * @return string
-	 */
-	protected function setDate()
-	{
-		$timezone = date('Z');
-		$operator = ($timezone[0] === '-') ? '-' : '+';
-		$timezone = abs($timezone);
-		$timezone = floor($timezone / 3600) * 100 + ($timezone % 3600) / 60;
-
-		return sprintf('%s %s%04d', date('D, j M Y H:i:s'), $operator, $timezone);
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Validate Email Address(es)
-	 *
-	 * @param string|array $email
-	 *
-	 * @return boolean
-	 */
-	public function validateEmail($email)
-	{
-		if (! is_array($email))
-		{
-			$email = [$email];
-		}
-
-		foreach ($email as $val)
-		{
-			if (! $this->isValidEmail($val))
-			{
-				throw MailerException::forInvalidAddress($val);
-			}
-		}
-
-		return true;
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Email Validation
-	 *
-	 * @param string $email
-	 *
-	 * @return boolean
-	 */
-	public function isValidEmail($email)
-	{
-		$email = $this->cleanEMail($email);
-
-		// sanitize the domain name
-		$atpos = strpos($email, '@');
-		$email = mb_substr($email, 0, ++ $atpos, '8bit') . idn_to_ascii(
-						mb_substr($email, $atpos), 0, INTL_IDNA_VARIANT_UTS46
-		);
-
-		return (bool) filter_var($email, FILTER_VALIDATE_EMAIL);
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Clean Extended Email Address: Joe Smith <joe@smith.com>
-	 *
-	 * @param string|array $email An email string, or array of them
-	 *
-	 * @return string|array The "clean" email-only address(es)
-	 */
-	public function cleanEmail($email)
-	{
-		if (! is_array($email))
-		{
-			return preg_match('/\<(.*)\>/', $email, $match) ? $match[1] : $email;
-		}
-
-		$cleanEmail = [];
-
-		foreach ($email as $addy)
-		{
-			$cleanEmail[] = preg_match('/\<(.*)\>/', $addy, $match) ? $match[1] : $addy;
-		}
-
-		return $cleanEmail;
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Word Wrap
-	 *
-	 * @param string       $str
-	 * @param integer|null $charlim Line-length limit
-	 *
-	 * @return string
-	 */
-	public function wordWrap($str, $charlim = null)
-	{
-		// Set the character limit, if not already present
-		if (empty($charlim))
-		{
-			$charlim = empty($this->wrapChars) ? 76 : $this->wrapChars;
-		}
-
-		// Standardize newlines
-		if (strpos($str, "\r") !== false)
-		{
-			$str = str_replace(["\r\n", "\r"], "\n", $str);
-		}
-
-		// Reduce multiple spaces at end of line
-		$str = preg_replace('| +\n|', "\n", $str);
-
-		// If the current word is surrounded by {unwrap} tags we'll
-		// strip the entire chunk and replace it with a marker.
-		$unwrap = [];
-		if (preg_match_all('|\{unwrap\}(.+?)\{/unwrap\}|s', $str, $matches))
-		{
-			for ($i = 0, $c = count($matches[0]); $i < $c; $i ++)
-			{
-				$unwrap[] = $matches[1][$i];
-				$str      = str_replace($matches[0][$i], '{{unwrapped' . $i . '}}', $str);
-			}
-		}
-
-		// Use PHP's native function to do the initial wordwrap.
-		// We set the cut flag to FALSE so that any individual words that are
-		// too long get left alone. In the next step we'll deal with them.
-		$str = wordwrap($str, $charlim, "\n", false);
-
-		// Split the string into individual lines of text and cycle through them
-		$output = '';
-		foreach (explode("\n", $str) as $line)
-		{
-			// Is the line within the allowed character count?
-			// If so we'll join it to the output and continue
-			if (mb_strlen($line) <= $charlim)
-			{
-				$output .= $line . $this->newline;
-				continue;
-			}
-
-			$temp = '';
-			do
-			{
-				// If the over-length word is a URL we won't wrap it
-				if (preg_match('!\[url.+\]|://|www\.!', $line))
-				{
-					break;
-				}
-
-				// Trim the word down
-				$temp .= mb_substr($line, 0, $charlim - 1, '8bit');
-				$line  = mb_substr($line, $charlim - 1);
-			}
-			while (mb_strlen($line) > $charlim);
-
-			// If $temp contains data it means we had to split up an over-length
-			// word into smaller chunks so we'll add it back to our current line
-			if ($temp !== '')
-			{
-				$output .= $temp . $this->newline;
-			}
-
-			$output .= $line . $this->newline;
-		}
-
-		// Put our markers back
-		if ($unwrap)
-		{
-			foreach ($unwrap as $key => $val)
-			{
-				$output = str_replace('{{unwrapped' . $key . '}}', $val, $output);
-			}
-		}
-
-		return $output;
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Send the message
-	 *
-	 * @param boolean $autoClear
-	 * @param boolean $reallySend
-	 *
-	 * @return boolean
-	 */
-	public function send($autoClear = true, bool $reallySend = true)
-	{
-		// our decision here, whether to send or fake it
-		$result = $reallySend ? $this->handler->send($this, $autoClear) : true;
-
-		if ($result && $autoClear)
-		{
-			$this->clear();
-		}
-
-		return $result;
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Mime Types
-	 *
-	 * @param string $ext
-	 *
-	 * @return string
-	 */
-	protected function mimeTypes($ext = '')
-	{
-		$mime = Mimes::guessTypeFromExtension(strtolower($ext));
-
-		return ! empty($mime) ? $mime : 'application/x-unknown-content-type';
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Lookup an email header and return its value.
-	 *
-	 * @param string $key
-	 *
-	 * @return string|null
-	 */
-	public function getHeader(string $key = ''): ?string
-	{
-		return $this->headers[$key] ?? null;
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Magic method to all protected/private class properties to be easily set,
-	 * if a property has a setter method.
-	 *
-	 * @param string $key
-	 * @param null   $value
-	 *
-	 * @return $this
-	 */
-	public function __set(string $key, $value = null)
-	{
-		$method = 'set' . str_replace(' ', '', ucwords(str_replace(['-', '_'], ' ', $key)));
-		if (method_exists($this, $method))
-		{
-			$this->$method($value);
-		}
-
-		return $this;
-	}
-
-	/**
-	 * Magic method to allow retrieval of protected
-	 * class properties either by their name, or through a `getCamelCasedProperty()`
-	 * method.
-	 *
-	 * @param string $key
-	 *
-	 * @return mixed
-	 */
-	public function __get(string $key)
-	{
-		// Convert to CamelCase for the method
-		$method = 'get' . str_replace(' ', '', ucwords(str_replace(['-', '_'], ' ', $key)));
-		if (method_exists($this, $method))
-		{
-			$result = $this->$method();
-		}
-		else if (property_exists($this, $key))
-		{
-			$result = $this->$key;
-		}
-
-		return $result ?? null;
-	}
-
-}

From 2148f4e9e66ceeed2240165a9d902038143d2940 Mon Sep 17 00:00:00 2001
From: MGatner <mgatner@icloud.com>
Date: Wed, 2 Jun 2021 02:09:43 +0000
Subject: [PATCH 4/8] Refactor base

---
 app/Config/Mailer.php                        |   35 +
 system/Config/Services.php                   |   16 +-
 system/Language/en/Mailer.php                |   10 +-
 system/Mailer/Address.php                    |   29 +-
 system/Mailer/Email.php                      |  100 +-
 system/Mailer/Exceptions/MailerException.php |   44 +-
 system/Mailer/Handlers/BaseHandler.php       | 1684 ++----------------
 system/Mailer/MailerInterface.php            |   26 +-
 8 files changed, 322 insertions(+), 1622 deletions(-)

diff --git a/app/Config/Mailer.php b/app/Config/Mailer.php
index 93f223f2116a..eb233465fcce 100644
--- a/app/Config/Mailer.php
+++ b/app/Config/Mailer.php
@@ -22,4 +22,39 @@ class Mailer
 	 * @var string
 	 */
 	public $handler = ENVIRONMENT === 'testing' ? 'dummy' : 'mail';
+
+	/**
+	 * The User Agent to specify when sending.
+	 *
+	 * @var string
+	 */
+	public $userAgent = 'CodeIgniter';
+
+	/**
+	 * Whether to send bulk BCC emails in batches.
+	 *
+	 * @var boolean
+	 */
+	public $batchMode = false;
+
+	/**
+	 * Number of emails in each BCC batch.
+	 *
+	 * @var integer
+	 */
+	public $batchSize = 200;
+
+	/**
+	 * System-specific criteria for handling encodings.
+	 *
+	 * @see \CodeIgniter\Mailer\Encoder::__construct()
+	 *
+	 * @var array<string,string>
+	 */
+	public $encoder = [
+		'charset'  => 'UTF-8',
+		'encoding' => '8bit',
+		'newline'  => "\r\n",
+		'crlf'     => "\r\n",
+	];
 }
diff --git a/system/Config/Services.php b/system/Config/Services.php
index 102af71fd800..8d24e40f185a 100644
--- a/system/Config/Services.php
+++ b/system/Config/Services.php
@@ -71,7 +71,7 @@
 use Config\Format as FormatConfig;
 use Config\Honeypot as HoneypotConfig;
 use Config\Images;
-use Config\Mailer as MailerConfig;
+use Config\Mailer as Mailer;
 use Config\Migrations;
 use Config\Pager as PagerConfig;
 use Config\Services as AppServices;
@@ -397,14 +397,14 @@ public static function logger(bool $getShared = true)
      *
      * @throws MailerException
      */
-    public static function mailer(MailerConfig $config = null, bool $getShared = true): MailerInterface
+    public static function mailer(Mailer $config = null, bool $getShared = true): MailerInterface
     {
         if ($getShared)
         {
             return static::getSharedInstance('mailer', $config);
         }
 
-        // Factories to load the configured default handler 
+        // Use Factories to load the default handler
         $config  = $config ?? config('Mailer');
         $handler = ucfirst($config->handler) . 'Handler';
         $options = [
@@ -414,12 +414,16 @@ public static function mailer(MailerConfig $config = null, bool $getShared = tru
             'preferApp'  => true,
         ];
 
-        if ($result = Factories::mailer($handler, $options, $config))
+        if (! $mailer = Factories::mailer($handler, $options, $config))
         {
-            return $result;
+            throw MailerException::forHandlerNotFound();
+        }
+        if (! $mailer->isSupported())
+        {
+            throw MailerException::forHandlerNotSupported(get_class($mailer));
         }
 
-        throw MailerException::forHandlerNotFound();
+        return $mailer;
     }
 
     //--------------------------------------------------------------------
diff --git a/system/Language/en/Mailer.php b/system/Language/en/Mailer.php
index 4bbb3d386f4e..0605cf73ec6a 100644
--- a/system/Language/en/Mailer.php
+++ b/system/Language/en/Mailer.php
@@ -10,14 +10,16 @@
  */
 
 return [
-	'handlerNotFound' => 'Mailer config has an invalid or missing handler.',
-	'invalidAddress'  => 'Invalid email address: {0}',
+	'handlerNotFound'     => 'Mailer config has an invalid or missing handler.',
+	'handlerNotSupported' => '{0} is not supported on your system.',
+	'invalidAddress'      => 'Invalid email address: {0}',
+	'noFrom'              => 'Cannot send mail with no "From" header.',
+	'noRecipients'        => 'You must include recipients: To, Cc, or Bcc',
+
 /*
 	'mustBeArray'          => 'The email validation method must be passed an array.',
 	'attachmentMissing'    => 'Unable to locate the following email attachment: {0}',
 	'attachmentUnreadable' => 'Unable to open this attachment: {0}',
-	'noFrom'               => 'Cannot send mail with no "From" header.',
-	'noRecipients'         => 'You must include recipients: To, Cc, or Bcc',
 	'sendFailurePHPMail'   => 'Unable to send email using PHP mail(). Your server might not be configured to send mail using this method.',
 	'sendFailureSendmail'  => 'Unable to send email using PHP Sendmail. Your server might not be configured to send mail using this method.',
 	'sendFailureSmtp'      => 'Unable to send email using PHP SMTP. Your server might not be configured to send mail using this method.',
diff --git a/system/Mailer/Address.php b/system/Mailer/Address.php
index 25c78714f9af..0039ba08a944 100644
--- a/system/Mailer/Address.php
+++ b/system/Mailer/Address.php
@@ -15,6 +15,11 @@
 
 class Address
 {
+	/**
+	 * Characters to trim from display names.
+	 */
+	private const TRIM = ' \'"';
+
 	/**
 	 * @var string
 	 */
@@ -75,7 +80,7 @@ final public static function split(string $address): array
 		{
 			return [
 				'email' => trim($matches[1]),
-				'name'  => trim(substr($address, 0, -1 * strlen($matches[0])), ' \'"'),
+				'name'  => trim(substr($address, 0, -1 * strlen($matches[0])), self::TRIM),
 			];
 		}
 
@@ -86,7 +91,8 @@ final public static function split(string $address): array
 	}
 
 	/**
-	 * Combines an email and (optional) display name into an address.
+	 * Combines an email and (optional) display name into an address
+	 * with wrapping quotes and angle brackets.
 	 * Trims content but does no validation or encoding.
 	 *
 	 * @param string $email
@@ -94,7 +100,22 @@ final public static function split(string $address): array
 	 */
 	final public static function merge(string $email, string $name = null): string
 	{
-		return empty($name) ? $email : $name . ' <' . $email . '>';
+		if (is_null($name))
+		{
+			return trim($email);
+		}
+
+		// Enclose the email in angle brackets
+		$email = '<' . $email . '>';
+
+		// If there is no name then finish
+		if ('' === $name = trim($name, SELF::TRIM))
+		{
+			return $email;
+		}
+
+		// Wrap the name in quotes and prepend it to the email
+		return '"' . $name . '" ' . $email;
 	}
 
 	/**
@@ -114,7 +135,7 @@ final public function __construct(string $email, string $name = null)
 			throw MailerException::forInvalidAddress($email);
 		}
 
-		$this->name  = isset($name) ? trim($name, ' \'"') : null;
+		$this->name = isset($name) ? trim($name, self::TRIM) : null;
 	}
 
 	/**
diff --git a/system/Mailer/Email.php b/system/Mailer/Email.php
index a338577ae9d6..0b74f51adab4 100644
--- a/system/Mailer/Email.php
+++ b/system/Mailer/Email.php
@@ -33,16 +33,43 @@ class Email extends Message
 	];
 
 	/**
-	 * Matches input keys to their setter method to store values.
+	 * This email's unique Message ID.
+	 *
+	 * @var string|null
+	 */
+	private $messageId;
+
+	/**
+	 * Stores any initial values.
 	 *
 	 * @param array $data
 	 */
 	public function __construct(array $data = [])
 	{
-		// Start with config defaults but prioritize any overrides
-		$data = array_merge(config('Mailer')->defaults, $data);
+		$this->set($data);
+	}
+
+	/**
+	 * Resets $messageId for clones to ensure each is unique.
+	 */
+	public function __clone()
+	{
+		unset($this->messageId);
+	}
 
-		// Check for any keys that match our setters
+	//--------------------------------------------------------------------
+
+	/**
+	 * Bulk stores values by matching input keys to their setter method.
+	 *
+	 * @param array $data
+	 * @param boolean $overwrite
+	 *
+	 * @return $this
+	 */
+	public function set(array $data, bool $overwrite = true): self
+	{
+		// Check for matching keys
 		foreach ([
 			'body',
 			'subject',
@@ -54,11 +81,16 @@ public function __construct(array $data = [])
 			'returnPath',
 			'priority',
 			'date',			
-		] as $method)
+		] as $setter)
 		{
-			if (array_key_exists($method, $data))
+			$getter = 'get' . ucfirst($setter);
+
+			if (array_key_exists($setter, $data))
 			{
-				$this->$method($data[$method]);
+				if ($overwrite || is_null($this->$getter()))
+				{
+					$this->$method($data[$method]);
+				}
 			}
 		}
 	}
@@ -76,7 +108,7 @@ public function __construct(array $data = [])
 	 */
 	public function setBody($body): self
 	{
-		return parent::setBody(rtrim(str_replace("\r", '', $body)));
+		return $this->body($body);
 	}
 
 	/**
@@ -86,7 +118,7 @@ public function setBody($body): self
 	 */
 	public function body(string $body)
 	{
-		return $this->setBody($body);
+		return parent::setBody(rtrim(str_replace("\r", '', $body)));
 	}
 
 	/**
@@ -150,13 +182,18 @@ public function replyTo(string $address)
 	}
 
 	/**
+	 * Return-Path must be only an email enclosed in angle brackets, e.g. "<admin@codeigniter.com>"
+	 *
 	 * @param string $address
 	 *
 	 * @return $this
 	 */
 	public function returnPath(string $address)
 	{
-	    return $this->setHeader('Return-Path', Address::create($address));
+		// Force Address to use angle braces by giving an empty display name
+		$email = Address::split($address)['email'];
+
+	    return $this->setHeader('Return-Path', new Address($email, ''));
 	}
 
 	/**
@@ -239,23 +276,33 @@ public function getReplyTo(): ?Address
 	 */
 	public function getReturnPath(): ?Address
 	{
-		return $this->hasHeader('Return-Path') ? Address::create($this->getHeader('Return-Path')->getValue()) : null;
+		if (! $this->hasHeader('Return-Path'))
+		{
+			return null;
+		}
+
+		// Get just the email portion of the stored address
+		$address = $this->getHeader('Return-Path')->getValue();
+		$email   = Address::split($address)['email'];
+
+		// Force Address to use angle braces by giving an empty display name
+	    return new Address($email, '');
 	}
 
 	/**
 	 * Returns the priority as an integer parsed from the header,
-	 * where 1 is the highest and 5 is the lowest. Default is 3.
+	 * where 1 is the highest and 5 is the lowest.
 	 *
 	 * @return int
 	 */
-	public function getPriority(): int
+	public function getPriority(): ?int
 	{
 		if ($this->hasHeader('X-Priority'))
 		{
-			return array_search($this->getHeader('X-Priority')->getValue(), self::PRIORITIES, true) ?: 3;
+			return array_search($this->getHeader('X-Priority')->getValue(), self::PRIORITIES, true) ?: null;
 		}
 
-		return 3;
+		return null;
 	}
 
 	/**
@@ -266,6 +313,23 @@ public function getDate(): ?Time
 		return $this->hasHeader('Date') ? Time::parse($this->getHeader('Date')->getValue()) : null;
 	}
 
+	/**
+	 * Gets or creates the unique Message ID.
+	 * Requires Return-Path to be set.
+	 *
+	 * @return string|null
+	 */
+	public function getMessageId(): ?string
+	{
+		if (is_null($this->messageId) && $returnPath = $this->getReturnPath())
+		{
+			// Use a unique ID with the same domain as the Return-Path email
+			$this->messageId = '<' . uniqid('', true) . strstr($returnPath->getEmail(), '@'). '>';
+		}
+
+		return $this->messageId;
+	}
+
 	//--------------------------------------------------------------------
 	// Backwards Compatibility
 	//--------------------------------------------------------------------
@@ -275,14 +339,14 @@ public function getDate(): ?Time
 	 *
 	 * @return $this
 	 */
-	public function setMessage($body)
+	public function setMessage($body): self
 	{
-		return $this->body(rtrim(str_replace("\r", '', $body)));
+		return $this->body($body);
 	}
 
 	/**
 	 * Magic method to allow CI3-style methods (like "setReplyTo()") to
-	 * forward to their new equivalent.
+	 * forward to their equivalent setters.
 	 *
 	 * @param string $name
 	 * @param array $arguments
diff --git a/system/Mailer/Exceptions/MailerException.php b/system/Mailer/Exceptions/MailerException.php
index ed65361a2c44..338595890759 100644
--- a/system/Mailer/Exceptions/MailerException.php
+++ b/system/Mailer/Exceptions/MailerException.php
@@ -25,9 +25,23 @@ public static function forHandlerNotFound()
 		return new static(lang('Mailer.handlerNotFound'));
 	}
 
+	/**
+	 * Thrown when specified handler is not supported.
+	 *
+	 * @param string $class
+	 *
+	 * @return static
+	 */
+	public static function forHandlerNotSupported(string $class)
+	{
+		return new static(lang('Mailer.handlerNotSupported', [$class]));
+	}
+
 	/**
 	 * Thrown when an email address fails validation
 	 *
+	 * @param string|null $value
+	 *
 	 * @return static
 	 */
 	public static function forInvalidAddress(string $value = null)
@@ -35,6 +49,26 @@ public static function forInvalidAddress(string $value = null)
 		return new static(lang('Mailer.invalidAddress', [$value]));
 	}
 
+	/**
+	 * Thrown when an Email is missing the "From" header
+	 *
+	 * @return static
+	 */
+	public static function forNoFrom()
+	{
+		return new static(lang('Mailer.noFrom'));
+	}
+
+	/**
+	 * Thrown when an Email has no "To", "Cc", and "Bcc" headers
+	 *
+	 * @return static
+	 */
+	public static function forNoRecipients()
+	{
+		return new static(lang('Mailer.noRecipients'));
+	}
+
 /*
 	public static function forAttachmentMissing(string $file = null)
 	{
@@ -57,16 +91,6 @@ public static function forInvalidProtocol(string $value = null)
 		return new static(lang('Mailer.invalidProtocolRequested', [$value]));
 	}
 
-	public static function forNoFrom()
-	{
-		return new static(lang('Mailer.noFrom', []));
-	}
-
-	public static function forNoRecipients()
-	{
-		return new static(lang('Mailer.noRecipients', []));
-	}
-
 	public static function forSendFailure(string $protocol = '?')
 	{
 		return new static(lang('Mailer.SendFailure', [$protocol]));
diff --git a/system/Mailer/Handlers/BaseHandler.php b/system/Mailer/Handlers/BaseHandler.php
index 3c56baea7975..54072206309a 100644
--- a/system/Mailer/Handlers/BaseHandler.php
+++ b/system/Mailer/Handlers/BaseHandler.php
@@ -1,333 +1,97 @@
 <?php
 
-namespace CodeIgniter\Mailer\Handlers;
-
 /**
- * CodeIgniter
- *
- * An open source application development framework for PHP
- *
- * This content is released under the MIT License (MIT)
+ * This file is part of the CodeIgniter 4 framework.
  *
- * Copyright (c) 2014 - 2018, British Columbia Institute of Technology
+ * (c) CodeIgniter Foundation <admin@codeigniter.com>
  *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in
- * all copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
- * THE SOFTWARE.
- *
- * @package    CodeIgniter
- * @author     EllisLab Dev Team
- * @copyright  Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright  Copyright (c) 2014 - 2018, British Columbia Institute of Technology (http://bcit.ca/)
- * @license    http://opensource.org/licenses/MIT    MIT License
- * @link       https://codeigniter.com
- * @since      Version 1.0.0
- * @filesource
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
  */
 
+namespace CodeIgniter\Mailer\Handlers;
+
+use CodeIgniter\Events\Events;
 use CodeIgniter\Mailer\Email;
 use CodeIgniter\Mailer\Exceptions\MailerException;
-use CodeIgniter\Mailer\MailerInterface;
-use Config\Mimes;
-use Psr\Log\LoggerAwareTrait;
-use Psr\Log\LoggerInterface;
+use Config\Mailer;
 
 /**
- * CodeIgniter Mailer Class
- *
- * Permits email to be sent using Mail, Sendmail, or SMTP.
+ * Mail Handler
  *
- * @package    CodeIgniter
- * @subpackage Libraries
- * @category   Libraries
- * @author     EllisLab Dev Team
- * @link       https://codeigniter.com/user_guide/libraries/email.html
+ * Handles sending email using the PHP mail() function.
  */
-class BaseHandler implements MailerInterface
+abstract class BaseHandler implements MailerInterface
 {
-
-	public $protocol = 'none';
-
 	/**
-	 * Message format.
+	 * The Mailer config.
 	 *
-	 * @var string 'text' or 'html'
+	 * @var Mailer|null
 	 */
-	public $mailType = 'text';
+	protected $config;
 
 	/**
-	 * Character set (default: utf-8)
+	 * The config-specific Encoder.
 	 *
-	 * @var string
+	 * @var Encoder
 	 */
-	public $charset = 'utf-8';
+	protected $encoder;
 
 	/**
-	 * Alternative message (for HTML messages only)
+	 * Protocol for this handler.
+	 * Set by child classes.
 	 *
 	 * @var string
 	 */
-	public $altMessage = '';
-
-	/**
-	 * Whether to validate e-mail addresses.
-	 *
-	 * @var boolean
-	 */
-	public $validate = true;
-
-	/**
-	 * X-Priority header value.
-	 *
-	 * @var integer 1-5
-	 */
-	public $priority = 3;            // Default priority (1 - 5)
-
-	/**
-	 * Newline character sequence.
-	 * Use "\r\n" to comply with RFC 822.
-	 *
-	 * @link http://www.ietf.org/rfc/rfc822.txt
-	 * @var  string "\r\n" or "\n"
-	 */
-	public $newline = "\n";            // Default newline. "\r\n" or "\n" (Use "\r\n" to comply with RFC 822)
-
-	/**
-	 * CRLF character sequence
-	 *
-	 * RFC 2045 specifies that for 'quoted-printable' encoding,
-	 * "\r\n" must be used. However, it appears that some servers
-	 * (even on the receiving end) don't handle it properly and
-	 * switching to "\n", while improper, is the only solution
-	 * that seems to work for all environments.
-	 *
-	 * @link http://www.ietf.org/rfc/rfc822.txt
-	 * @var  string
-	 */
-	public $CRLF = "\n";
-
-	/**
-	 * Whether to use Delivery Status Notification.
-	 *
-	 * @var boolean
-	 */
-	public $DSN = false;
-
-	/**
-	 * Whether to send multipart alternatives.
-	 * Yahoo! doesn't seem to like these.
-	 *
-	 * @var boolean
-	 */
-	public $sendMultipart = true;
-
-	/**
-	 * Whether to send messages to BCC recipients in batches.
-	 *
-	 * @var boolean
-	 */
-	public $BCCBatchMode = false;
-
-	/**
-	 * BCC Batch max number size.
-	 *
-	 * @see self::$BCCBatchMode
-	 * @var integer
-	 */
-	public $BCCBatchSize = 200;
+	protected $protocol;
 
 	//--------------------------------------------------------------------
 
 	/**
-	 * Subject header
-	 *
-	 * @var string
-	 */
-	protected $subject = '';
-
-	/**
-	 * Message body
-	 *
-	 * @var string
-	 */
-	protected $body = '';
-
-	/**
-	 * Final message body to be sent.
-	 *
-	 * @var string
-	 */
-	protected $finalBody = '';
-
-	/**
-	 * Final headers to send
-	 *
-	 * @var string
-	 */
-	protected $headerStr = '';
-
-	/**
-	 * SMTP Connection socket placeholder
-	 *
-	 * @var resource
-	 */
-	protected $SMTPConnect = '';
-
-	/**
-	 * Mail encoding
-	 *
-	 * @var string '8bit' or '7bit'
-	 */
-	protected $encoding = '8bit';
-
-	/**
-	 * Whether to send a Reply-To header
-	 *
-	 * @var boolean
-	 */
-	protected $replyToFlag = false;
-
-	/**
-	 * Debug messages
-	 *
-	 * @see self::printDebugger()
-	 * @var array
-	 */
-	protected $debugMessage = [];
-
-	/**
-	 * Recipients
-	 *
-	 * @var array
-	 */
-	protected $recipients = [];
-
-	/**
-	 * CC Recipients
-	 *
-	 * @var array
-	 */
-	protected $CCArray = [];
-
-	/**
-	 * BCC Recipients
-	 *
-	 * @var array
-	 */
-	protected $BCCArray = [];
-
-	/**
-	 * Message headers
-	 *
-	 * @var array
-	 */
-	protected $headers = [];
-
-	/**
-	 * Attachment data
-	 *
-	 * @var array
-	 */
-	protected $attachments = [];
-
-	/**
-	 * Valid $protocol values
-	 *
-	 * @see self::$protocol
-	 * @var array
-	 */
-	protected $protocols = [
-		'mail',
-		'sendmail',
-		'smtp',
-	];
-
-	/**
-	 * Base charsets
+	 * Whether this handler is supported on this system.
 	 *
-	 * Character sets valid for 7-bit encoding,
-	 * excluding language suffix.
-	 *
-	 * @var array
+	 * @return boolean
 	 */
-	protected $baseCharsets = [
-		'us-ascii',
-		'iso-2022-',
-	];
+	abstract public function isSupported(): bool;
 
 	/**
-	 * Bit depths
+	 * Spools an Email to the server.
 	 *
-	 * Valid mail encodings
+	 * @param Email $email
 	 *
-	 * @see self::$encoding
-	 * @var array
+	 * @return boolean
 	 */
-	protected $bitDepths = [
-		'7bit',
-		'8bit',
-	];
+	abstract protected function spool(Email $email);
 
-	/**
-	 * $priority translations
-	 *
-	 * Actual values to send with the X-Priority header
-	 *
-	 * @var array
-	 */
-	protected $priorities = [
-		1 => '1 (Highest)',
-		2 => '2 (High)',
-		3 => '3 (Normal)',
-		4 => '4 (Low)',
-		5 => '5 (Lowest)',
-	];
+	//--------------------------------------------------------------------
 
 	/**
-	 * mbstring.func_overload flag
+	 * Stores the Mailer config.
 	 *
-	 * @var boolean
+	 * @param Mailer $config
 	 */
-	protected static $func_overload;
+	public function __construct(Mailer $config)
+	{
+		$this->config  = clone $config;
+		$this->encoder = new Encoder($this->config->encoder);
+	}
 
 	/**
-	 * Logger instance to record error messages and awarnings.
+	 * Gets the Mailer config.
 	 *
-	 * @var \PSR\Log\LoggerInterface
+	 * @return Mailer
 	 */
-	protected $logger;
-
-	//--------------------------------------------------------------------
+	public function getConfig(Mailer $config): Mailer
+	{
+		return $this->config;
+	}
 
 	/**
-	 * Constructor - Sets Preferences
-	 *
-	 * The constructor can be passed an array of config values
+	 * Gets the protocol.
 	 *
-	 * @param array|null $config
+	 * @return string
 	 */
-	public function __construct($config = null)
-	{
-		$this->initialize($config);
-
-		log_message('info', 'Mailer Class Initialized');
-	}
-
-	public function getProtocol() : string
+	public function getProtocol(): string
 	{
 		return $this->protocol;
 	}
@@ -335,1341 +99,103 @@ public function getProtocol() : string
 	//--------------------------------------------------------------------
 
 	/**
-	 * Initialize preferences
-	 *
-	 * @param array|\Config\Mailer $config
+	 * Sends an Email.
 	 *
-	 * @return $this
+	 * @param Email $email
 	 */
-	public function initialize($config)
+	public function send(Email $email)
 	{
-		$this->clear();
+		$this->buildHeaders($email);
+		$this->buildMessage($email);
 
-		if ($config instanceof \Config\Mailer)
+		// Check for a batch request
+		if ($this->config->batchMode)
 		{
-			$config = get_object_vars($config);
-		}
+			// Temporarily disable batch mode to prevent recursion
+			$this->config->batchMode = false;
+			$bccs = $email->getBcc();
 
-		foreach (get_class_vars(get_class($this)) as $key => $value)
-		{
-			if (property_exists($this, $key) && isset($config[$key]))
+			try
 			{
-				$method = 'set' . ucfirst($key);
-
-				if (method_exists($this, $method))
+				foreach (array_chunk($bccs, $this->config->batchSize) as $bcc)
 				{
-					$this->$method($config[$key]);
+					$batch = clone $email;
+					$batch->bcc($bcc);
+
+					$this->send($batch);
 				}
 			}
+			// Restore batch mode
+			finally
+			{
+				$this->config->batchMode = true;
+			}
+
+			return;
 		}
 
-		$this->charset  = strtoupper($this->charset);
-		$this->SMTPAuth = isset($this->SMTPUser[0], $this->SMTPPass[0]);
+		$result = $this->spool($email);
 
-		return $this;
-	}
 
-	public function setLogger(LoggerInterface $logger)
-	{
-		$this->logger = $logger;
-	}
-	//--------------------------------------------------------------------
 
-	/**
-	 * Initialize the Data
-	 *
-	 * @param boolean $clearAttachments
-	 *
-	 * @return $this
-	 */
-	public function clear($clearAttachments = false)
-	{
-		$this->subject      = '';
-		$this->body         = '';
-		$this->finalBody    = '';
-		$this->headerStr    = '';
-		$this->replyToFlag  = false;
-		$this->recipients   = [];
-		$this->CCArray      = [];
-		$this->BCCArray     = [];
-		$this->headers      = [];
-		$this->debugMessage = [];
+		if ($result)
+		{
+			$this->setArchiveValues();
 
-		$this->setHeader('Date', $this->setDate());
+			if ($autoClear)
+			{
+				$this->clear();
+			}
 
-		if ($clearAttachments !== false)
-		{
-			$this->attachments = [];
+			Events::trigger('email_sent', $email);
 		}
 
-		return $this;
-	}
-
-	//--------------------------------------------------------------------
+		return $result;
 
-	/**
-	 * Build final headers
-	 */
-	protected function buildHeaders()
-	{
-		$this->setHeader('User-Agent', $this->userAgent);
-		$this->setHeader('X-Sender', $this->cleanEmail($this->headers['From']));
-		$this->setHeader('X-Mailer', $this->userAgent);
-		$this->setHeader('X-Priority', $this->priorities[$this->priority]);
-		$this->setHeader('Message-ID', $this->getMessageID());
-		$this->setHeader('Mime-Version', '1.0');
 	}
 
-	//--------------------------------------------------------------------
-
 	/**
-	 * Write Headers as a string
+	 * Builds the remaining Email headers (including config defaults)
+	 * and validates all required headers are present.
+	 *
+	 * @return Mailer
+	 *
+	 * @throws MailerException
 	 */
-	protected function writeHeaders()
+	protected function buildHeaders(Email $email): self
 	{
-		if ($this->protocol === 'mail')
-		{
-			if (isset($this->headers['Subject']))
-			{
-				$this->subject = $this->headers['Subject'];
-				unset($this->headers['Subject']);
-			}
-		}
-
-		reset($this->headers);
-		$this->headerStr = '';
+		// Apply any missing defaults from the config
+		$email->set($this->config->defaults, false);
 
-		foreach ($this->headers as $key => $val)
+		// Must have a sender
+		if (is_null($email->getFrom()))
 		{
-			$val = trim($val);
-
-			if ($val !== '')
-			{
-				$this->headerStr .= $key . ': ' . $val . $this->newline;
-			}
+			throw MailerException::forNoFrom();
 		}
-
-		if ($this->getProtocol() === 'mail')
+		// Must have at least one recipient
+		if (empty($email->getTo()) && empty($email->getCc()) && empty($email->getBcc()))
 		{
-			$this->headerStr = rtrim($this->headerStr);
+			throw MailerException::forNoRecipients();
 		}
-	}
-
-	//--------------------------------------------------------------------
 
-	/**
-	 * Build Final Body and attachments
-	 */
-	protected function buildMessage()
-	{
-		if ($this->wordWrap === true && $this->mailType !== 'html')
+		// If no "reply to" header was set then use the From value
+		if (is_null($email->getReplyTo()) && $from = $email->getFrom())
 		{
-			$this->body = $this->wordWrap($this->body);
+			$email->setReplyTo($from);
 		}
-
-		$this->writeHeaders();
-
-		$hdr  = ($this->getProtocol() === 'mail') ? $this->newline : '';
-		$body = '';
-
-		switch ($this->getContentType())
+		// If no priority header was set then use "normal"
+		if (is_null($email->getPriority()))
 		{
-			case 'plain':
-
-				$hdr .= 'Content-Type: text/plain; charset=' . $this->charset . $this->newline
-						. 'Content-Transfer-Encoding: ' . $this->getEncoding();
-
-				if ($this->getProtocol() === 'mail')
-				{
-					$this->headerStr .= $hdr;
-					$this->finalBody  = $this->body;
-				}
-				else
-				{
-					$this->finalBody = $hdr . $this->newline . $this->newline . $this->body;
-				}
-
-				return;
-
-			case 'html':
-
-				if ($this->sendMultipart === false)
-				{
-					$hdr .= 'Content-Type: text/html; charset=' . $this->charset . $this->newline
-							. 'Content-Transfer-Encoding: quoted-printable';
-				}
-				else
-				{
-					$boundary = uniqid('B_ALT_', true);
-					$hdr     .= 'Content-Type: multipart/alternative; boundary="' . $boundary . '"';
-
-					$body .= $this->getMimeMessage() . $this->newline . $this->newline
-							. '--' . $boundary . $this->newline
-							. 'Content-Type: text/plain; charset=' . $this->charset . $this->newline
-							. 'Content-Transfer-Encoding: ' . $this->getEncoding() . $this->newline . $this->newline
-							. $this->getAltMessage() . $this->newline . $this->newline
-							. '--' . $boundary . $this->newline
-							. 'Content-Type: text/html; charset=' . $this->charset . $this->newline
-							. 'Content-Transfer-Encoding: quoted-printable' . $this->newline . $this->newline;
-				}
-
-				$this->finalBody = $body . $this->prepQuotedPrintable($this->body) . $this->newline . $this->newline;
-
-				if ($this->getProtocol() === 'mail')
-				{
-					$this->headerStr .= $hdr;
-				}
-				else
-				{
-					$this->finalBody = $hdr . $this->newline . $this->newline . $this->finalBody;
-				}
-
-				if ($this->sendMultipart !== false)
-				{
-					$this->finalBody .= '--' . $boundary . '--';
-				}
-
-				return;
-
-			case 'plain-attach':
-
-				$boundary = uniqid('B_ATC_', true);
-				$hdr     .= 'Content-Type: multipart/mixed; boundary="' . $boundary . '"';
-
-				if ($this->getProtocol() === 'mail')
-				{
-					$this->headerStr .= $hdr;
-				}
-
-				$body .= $this->getMimeMessage() . $this->newline
-						. $this->newline
-						. '--' . $boundary . $this->newline
-						. 'Content-Type: text/plain; charset=' . $this->charset . $this->newline
-						. 'Content-Transfer-Encoding: ' . $this->getEncoding() . $this->newline
-						. $this->newline
-						. $this->body . $this->newline . $this->newline;
-
-				$this->appendAttachments($body, $boundary);
-
-				break;
-			case 'html-attach':
-
-				$alt_boundary  = uniqid('B_ALT_', true);
-				$last_boundary = null;
-
-				if ($this->attachmentsHaveMultipart('mixed'))
-				{
-					$atc_boundary  = uniqid('B_ATC_', true);
-					$hdr          .= 'Content-Type: multipart/mixed; boundary="' . $atc_boundary . '"';
-					$last_boundary = $atc_boundary;
-				}
-
-				if ($this->attachmentsHaveMultipart('related'))
-				{
-					$rel_boundary        = uniqid('B_REL_', true);
-					$rel_boundary_header = 'Content-Type: multipart/related; boundary="' . $rel_boundary . '"';
-
-					if (isset($last_boundary))
-					{
-						$body .= '--' . $last_boundary . $this->newline . $rel_boundary_header;
-					}
-					else
-					{
-						$hdr .= $rel_boundary_header;
-					}
-
-					$last_boundary = $rel_boundary;
-				}
-
-				if ($this->getProtocol() === 'mail')
-				{
-					$this->headerStr .= $hdr;
-				}
-
-				static::strlen($body) && $body .= $this->newline . $this->newline;
-				$body                          .= $this->getMimeMessage() . $this->newline . $this->newline
-						. '--' . $last_boundary . $this->newline
-						. 'Content-Type: multipart/alternative; boundary="' . $alt_boundary . '"' . $this->newline . $this->newline
-						. '--' . $alt_boundary . $this->newline
-						. 'Content-Type: text/plain; charset=' . $this->charset . $this->newline
-						. 'Content-Transfer-Encoding: ' . $this->getEncoding() . $this->newline . $this->newline
-						. $this->getAltMessage() . $this->newline . $this->newline
-						. '--' . $alt_boundary . $this->newline
-						. 'Content-Type: text/html; charset=' . $this->charset . $this->newline
-						. 'Content-Transfer-Encoding: quoted-printable' . $this->newline . $this->newline
-						. $this->prepQuotedPrintable($this->body) . $this->newline . $this->newline
-						. '--' . $alt_boundary . '--' . $this->newline . $this->newline;
-
-				if (! empty($rel_boundary))
-				{
-					$body .= $this->newline . $this->newline;
-					$this->appendAttachments($body, $rel_boundary, 'related');
-				}
-
-				// multipart/mixed attachments
-				if (! empty($atc_boundary))
-				{
-					$body .= $this->newline . $this->newline;
-					$this->appendAttachments($body, $atc_boundary, 'mixed');
-				}
-
-				break;
+			$email->setPriority(3);
 		}
 
-		$this->finalBody = ($this->getProtocol() === 'mail') ? $body : $hdr . $this->newline . $this->newline . $body;
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Prepares attachment string
-	 *
-	 * @param string      &$body     Message body to append to
-	 * @param string      $boundary  Multipart boundary
-	 * @param string|null $multipart When provided, only attachments of this type will be processed
-	 *
-	 * @return string
-	 */
-	protected function appendAttachments(&$body, $boundary, $multipart = null)
-	{
-		for ($i = 0, $c = count($this->attachments); $i < $c; $i ++)
-		{
-			if (isset($multipart) && $this->attachments[$i]['multipart'] !== $multipart)
-			{
-				continue;
-			}
-
-			$name = isset($this->attachments[$i]['name'][1]) ? $this->attachments[$i]['name'][1] : basename($this->attachments[$i]['name'][0]);
-
-			$body .= '--' . $boundary . $this->newline
-					. 'Content-Type: ' . $this->attachments[$i]['type'] . '; name="' . $name . '"' . $this->newline
-					. 'Content-Disposition: ' . $this->attachments[$i]['disposition'] . ';' . $this->newline
-					. 'Content-Transfer-Encoding: base64' . $this->newline
-					. (empty($this->attachments[$i]['cid']) ? '' : 'Content-ID: <' . $this->attachments[$i]['cid'] . '>' . $this->newline)
-					. $this->newline
-					. $this->attachments[$i]['content'] . $this->newline;
-		}
+		// Set transport headers directly
+		$email->setHeader('User-Agent', $this->config->userAgent);
+		$email->setHeader('X-Mailer', $this->config->userAgent);
+		$email->setHeader('X-Sender', $email->getFrom()->getEmail());
+		$email->setHeader('Message-ID', $this->getMessageID());
+		$email->setHeader('Mime-Version', '1.0');
 
-		// $name won't be set if no attachments were appended,
-		// and therefore a boundary wouldn't be necessary
-		empty($name) || $body .= '--' . $boundary . '--';
+		return $this;
 	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Prep Quoted Printable
-	 *
-	 * Prepares string for Quoted-Printable Content-Transfer-Encoding
-	 * Refer to RFC 2045 http://www.ietf.org/rfc/rfc2045.txt
-	 *
-	 * @param string $str
-	 *
-	 * @return string
-	 */
-	protected function prepQuotedPrintable($str)
-	{
-		// ASCII code numbers for "safe" characters that can always be
-		// used literally, without encoding, as described in RFC 2049.
-		// http://www.ietf.org/rfc/rfc2049.txt
-		static $ascii_safe_chars = [
-			// ' (  )   +   ,   -   .   /   :   =   ?
-			39,
-			40,
-			41,
-			43,
-			44,
-			45,
-			46,
-			47,
-			58,
-			61,
-			63,
-			// numbers
-			48,
-			49,
-			50,
-			51,
-			52,
-			53,
-			54,
-			55,
-			56,
-			57,
-			// upper-case letters
-			65,
-			66,
-			67,
-			68,
-			69,
-			70,
-			71,
-			72,
-			73,
-			74,
-			75,
-			76,
-			77,
-			78,
-			79,
-			80,
-			81,
-			82,
-			83,
-			84,
-			85,
-			86,
-			87,
-			88,
-			89,
-			90,
-			// lower-case letters
-			97,
-			98,
-			99,
-			100,
-			101,
-			102,
-			103,
-			104,
-			105,
-			106,
-			107,
-			108,
-			109,
-			110,
-			111,
-			112,
-			113,
-			114,
-			115,
-			116,
-			117,
-			118,
-			119,
-			120,
-			121,
-			122,
-		];
-
-		// We are intentionally wrapping so mail servers will encode characters
-		// properly and MUAs will behave, so {unwrap} must go!
-		$str = str_replace(['{unwrap}', '{/unwrap}'], '', $str);
-
-		// RFC 2045 specifies CRLF as "\r\n".
-		// However, many developers choose to override that and violate
-		// the RFC rules due to (apparently) a bug in MS Exchange,
-		// which only works with "\n".
-		if ($this->CRLF === "\r\n")
-		{
-			return quoted_printable_encode($str);
-		}
-
-		// Reduce multiple spaces & remove nulls
-		$str = preg_replace(['| +|', '/\x00+/'], [' ', ''], $str);
-
-		// Standardize newlines
-		if (strpos($str, "\r") !== false)
-		{
-			$str = str_replace(["\r\n", "\r"], "\n", $str);
-		}
-
-		$escape = '=';
-		$output = '';
-
-		foreach (explode("\n", $str) as $line)
-		{
-			$length = static::strlen($line);
-			$temp   = '';
-
-			// Loop through each character in the line to add soft-wrap
-			// characters at the end of a line " =\r\n" and add the newly
-			// processed line(s) to the output (see comment on $crlf class property)
-			for ($i = 0; $i < $length; $i ++)
-			{
-				// Grab the next character
-				$char  = $line[$i];
-				$ascii = ord($char);
-
-				// Convert spaces and tabs but only if it's the end of the line
-				if ($ascii === 32 || $ascii === 9)
-				{
-					if ($i === ($length - 1))
-					{
-						$char = $escape . sprintf('%02s', dechex($ascii));
-					}
-				}
-				// DO NOT move this below the $ascii_safe_chars line!
-				//
-				// = (equals) signs are allowed by RFC2049, but must be encoded
-				// as they are the encoding delimiter!
-				elseif ($ascii === 61)
-				{
-					$char = $escape . strtoupper(sprintf('%02s', dechex($ascii)));  // =3D
-				}
-				elseif (! in_array($ascii, $ascii_safe_chars, true))
-				{
-					$char = $escape . strtoupper(sprintf('%02s', dechex($ascii)));
-				}
-
-				// If we're at the character limit, add the line to the output,
-				// reset our temp variable, and keep on chuggin'
-				if ((static::strlen($temp) + static::strlen($char)) >= 76)
-				{
-					$output .= $temp . $escape . $this->CRLF;
-					$temp    = '';
-				}
-
-				// Add the character to our temporary line
-				$temp .= $char;
-			}
-
-			// Add our completed line to the output
-			$output .= $temp . $this->CRLF;
-		}
-
-		// get rid of extra CRLF tacked onto the end
-		return static::substr($output, 0, static::strlen($this->CRLF) * -1);
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Sends an Email
-	 *
-	 * @param Email $email
-	 *
-	 * @return boolean
-	 */
-	public function send(Email $email)
-	{
-		if (! isset($this->headers['From']) && ! empty($this->fromEmail))
-		{
-			$this->setFrom($this->fromEmail, $this->fromName);
-		}
-
-		if (! isset($this->headers['From']))
-		{
-				throw MailerException::forNoFrom();
-		}
-
-		if ($this->replyToFlag === false)
-		{
-			$this->setReplyTo($this->headers['From']);
-		}
-
-		if (empty($this->recipients) && ! isset($this->headers['To']) && empty($this->BCCArray) && ! isset($this->headers['Bcc']) && ! isset($this->headers['Cc'])
-		)
-		{
-				throw MailerException::forNoRecipients();
-		}
-
-		$this->buildHeaders();
-
-		if ($this->BCCBatchMode && count($this->BCCArray) > $this->BCCBatchSize)
-		{
-			$this->batchBCCSend();
-
-			if ($autoClear)
-			{
-				$this->clear();
-			}
-
-			return true;
-		}
-
-		$this->buildMessage();
-		$result = $this->spoolEmail();
-
-		if ($result && $autoClear)
-		{
-			$this->clear();
-		}
-
-		return $result;
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Batch Bcc Send. Sends groups of BCCs in batches
-	 */
-	public function batchBCCSend()
-	{
-		$float = $this->BCCBatchSize - 1;
-		$set   = '';
-		$chunk = [];
-
-		for ($i = 0, $c = count($this->BCCArray); $i < $c; $i ++)
-		{
-			if (isset($this->BCCArray[$i]))
-			{
-				$set .= ', ' . $this->BCCArray[$i];
-			}
-
-			if ($i === $float)
-			{
-				$chunk[] = static::substr($set, 1);
-				$float  += $this->BCCBatchSize;
-				$set     = '';
-			}
-
-			if ($i === $c - 1)
-			{
-				$chunk[] = static::substr($set, 1);
-			}
-		}
-
-		for ($i = 0, $c = count($chunk); $i < $c; $i ++)
-		{
-			unset($this->headers['Bcc']);
-
-			$bcc = $this->cleanEmail($this->stringToArray($chunk[$i]));
-
-			if ($this->protocol !== 'smtp')
-			{
-				$this->setHeader('Bcc', implode(', ', $bcc));
-			}
-			else
-			{
-				$this->BCCArray = $bcc;
-			}
-
-			$this->buildMessage();
-			$this->spoolEmail();
-		}
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Unwrap special elements
-	 */
-	protected function unwrapSpecials()
-	{
-		$this->finalBody = preg_replace_callback(
-				'/\{unwrap\}(.*?)\{\/unwrap\}/si', [
-					$this,
-					'removeNLCallback',
-				], $this->finalBody
-		);
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Strip line-breaks via callback
-	 *
-	 * @param string $matches
-	 *
-	 * @return string
-	 */
-	protected function removeNLCallback($matches)
-	{
-		if (strpos($matches[1], "\r") !== false || strpos($matches[1], "\n") !== false)
-		{
-			$matches[1] = str_replace(["\r\n", "\r", "\n"], '', $matches[1]);
-		}
-
-		return $matches[1];
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Spool mail to the mail server
-	 *
-	 * @return boolean
-	 */
-	protected function spoolEmail()
-	{
-		$this->unwrapSpecials();
-
-		$protocol = $this->getProtocol();
-		$method   = 'sendWith' . ucfirst($protocol);
-		try
-		{
-			$success = $this->$method();
-		}
-		catch (\ErrorException $e)
-		{
-			$success = false;
-			$this->logger->error('Mailer: ' . $method . ' throwed ' . $e->getMessage());
-		}
-
-		if (! $success)
-		{
-				throw MailerException::forSendFailure($protocol === 'mail' ? 'PHPMail' : ucfirst($protocol));
-		}
-
-		$this->setErrorMessage(lang('Mailer.sent', [$protocol]));
-
-		return true;
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Validate email for shell
-	 *
-	 * Applies stricter, shell-safe validation to email addresses.
-	 * Introduced to prevent RCE via sendmail's -f option.
-	 *
-	 * @see     https://github.com/codeigniter4/CodeIgniter/issues/4963
-	 * @see     https://gist.github.com/Zenexer/40d02da5e07f151adeaeeaa11af9ab36
-	 * @license https://creativecommons.org/publicdomain/zero/1.0/    CC0 1.0, Public Domain
-	 *
-	 * Credits for the base concept go to Paul Buonopane <paul@namepros.com>
-	 *
-	 * @param string &$email
-	 *
-	 * @return boolean
-	 */
-	protected function validateEmailForShell(&$email)
-	{
-		if (function_exists('idn_to_ascii') && $atpos = strpos($email, '@'))
-		{
-			$email = static::substr($email, 0, ++ $atpos) . idn_to_ascii(
-							static::substr($email, $atpos), 0, INTL_IDNA_VARIANT_UTS46
-			);
-		}
-
-		return (filter_var($email, FILTER_VALIDATE_EMAIL) === $email && preg_match('#\A[a-z0-9._+-]+@[a-z0-9.-]{1,253}\z#i', $email));
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Send using mail()
-	 *
-	 * @return boolean
-	 */
-	protected function sendWithMail()
-	{
-		if (is_array($this->recipients))
-		{
-			$this->recipients = implode(', ', $this->recipients);
-		}
-
-		// _validate_email_for_shell() below accepts by reference,
-		// so this needs to be assigned to a variable
-		$from = $this->cleanEmail($this->headers['Return-Path']);
-
-		if (! $this->validateEmailForShell($from))
-		{
-			return mail($this->recipients, $this->subject, $this->finalBody, $this->headerStr);
-		}
-
-		// most documentation of sendmail using the "-f" flag lacks a space after it, however
-		// we've encountered servers that seem to require it to be in place.
-		return mail($this->recipients, $this->subject, $this->finalBody, $this->headerStr, '-f ' . $from);
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Send using Sendmail
-	 *
-	 * @return boolean
-	 */
-	protected function sendWithSendmail()
-	{
-		// _validate_email_for_shell() below accepts by reference,
-		// so this needs to be assigned to a variable
-		$from = $this->cleanEmail($this->headers['From']);
-		if ($this->validateEmailForShell($from))
-		{
-			$from = '-f ' . $from;
-		}
-		else
-		{
-			$from = '';
-		}
-
-		// is popen() enabled?
-		if (! function_usable('popen') || false === ($fp = @popen($this->mailPath . ' -oi ' . $from . ' -t', 'w')))
-		{
-			// server probably has popen disabled, so nothing we can do to get a verbose error.
-			return false;
-		}
-
-		fputs($fp, $this->headerStr);
-		fputs($fp, $this->finalBody);
-
-		$status = pclose($fp);
-
-		if ($status !== 0)
-		{
-				throw MailerException::forNosocket($status);
-		}
-
-		return true;
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Send using SMTP
-	 *
-	 * @return boolean
-	 */
-	protected function sendWithSmtp()
-	{
-		if ($this->SMTPHost === '')
-		{
-				throw MailerException::forNoHostname();
-		}
-
-		if (! $this->SMTPConnect() || ! $this->SMTPAuthenticate())
-		{
-			return false;
-		}
-
-		if (! $this->sendCommand('from', $this->cleanFrameworkException($this->headers['From'])))
-		{
-			$this->SMTPEnd();
-
-			return false;
-		}
-
-		foreach ($this->recipients as $val)
-		{
-			if (! $this->sendCommand('to', $val))
-			{
-				$this->SMTPEnd();
-
-				return false;
-			}
-		}
-
-		foreach ($this->CCArray as $val)
-		{
-			if ($val !== '' && ! $this->sendCommand('to', $val))
-			{
-				$this->SMTPEnd();
-
-				return false;
-			}
-		}
-
-		foreach ($this->BCCArray as $val)
-		{
-			if ($val !== '' && ! $this->sendCommand('to', $val))
-			{
-				$this->SMTPEnd();
-
-				return false;
-			}
-		}
-
-		if (! $this->sendCommand('data'))
-		{
-			$this->SMTPEnd();
-
-			return false;
-		}
-
-		// perform dot transformation on any lines that begin with a dot
-		$this->sendData($this->headerStr . preg_replace('/^\./m', '..$1', $this->finalBody));
-
-		$this->sendData('.');
-		$reply = $this->getSMTPData();
-		$this->setErrorMessage($reply);
-
-		$this->SMTPEnd();
-
-		if (strpos($reply, '250') !== 0)
-		{
-				throw FrameworkExceptionException::forSMTPError($reply);
-		}
-
-		return true;
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * SMTP End
-	 *
-	 * Shortcut to send RSET or QUIT depending on keep-alive
-	 */
-	protected function SMTPEnd()
-	{
-		$this->sendCommand($this->SMTPKeepAlive ? 'reset' : 'quit');
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * SMTP Connect
-	 *
-	 * @return string
-	 */
-	protected function SMTPConnect()
-	{
-		if (is_resource($this->SMTPConnect))
-		{
-			return true;
-		}
-
-		$ssl = ($this->SMTPCrypto === 'ssl') ? 'ssl://' : '';
-
-		$this->SMTPConnect = fsockopen(
-				$ssl . $this->SMTPHost, $this->SMTPPort, $errno, $errstr, $this->SMTPTimeout
-		);
-
-		if (! is_resource($this->SMTPConnect))
-		{
-				throw FrameworkExceptionException::forSMTPError($errno . ' ' . $errstr);
-		}
-
-		stream_set_timeout($this->SMTPConnect, $this->SMTPTimeout);
-		$this->setErrorMessage($this->getSMTPData());
-
-		if ($this->SMTPCrypto === 'tls')
-		{
-			$this->sendCommand('hello');
-			$this->sendCommand('starttls');
-
-			$crypto = stream_socket_enable_crypto($this->SMTPConnect, true, STREAM_CRYPTO_METHOD_TLS_CLIENT);
-
-			if ($crypto !== true)
-			{
-				throw FrameworkExceptionException::forSMTPError($this->getSMTPData());
-			}
-		}
-
-		return $this->sendCommand('hello');
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Send SMTP command
-	 *
-	 * @param string $cmd
-	 * @param string $data
-	 *
-	 * @return boolean
-	 */
-	protected function sendCommand($cmd, $data = '')
-	{
-		switch ($cmd)
-		{
-			case 'hello':
-				if ($this->SMTPAuth || $this->getEncoding() === '8bit')
-				{
-					$this->sendData('EHLO ' . $this->getHostname());
-				}
-				else
-				{
-					$this->sendData('HELO ' . $this->getHostname());
-				}
-
-				$resp = 250;
-				break;
-			case 'starttls':
-				$this->sendData('STARTTLS');
-				$resp = 220;
-				break;
-			case 'from':
-				$this->sendData('MAIL FROM:<' . $data . '>');
-				$resp = 250;
-				break;
-			case 'to':
-				if ($this->DSN)
-				{
-					$this->sendData('RCPT TO:<' . $data . '> NOTIFY=SUCCESS,DELAY,FAILURE ORCPT=rfc822;' . $data);
-				}
-				else
-				{
-					$this->sendData('RCPT TO:<' . $data . '>');
-				}
-				$resp = 250;
-				break;
-			case 'data':
-				$this->sendData('DATA');
-				$resp = 354;
-				break;
-			case 'reset':
-				$this->sendData('RSET');
-				$resp = 250;
-				break;
-			case 'quit':
-				$this->sendData('QUIT');
-				$resp = 221;
-				break;
-		}
-
-		$reply = $this->getSMTPData();
-
-		$this->debugMessage[] = '<pre>' . $cmd . ': ' . $reply . '</pre>';
-
-		if ((int) static::substr($reply, 0, 3) !== $resp)
-		{
-				throw FrameworkExceptionException::forSMTPError($reply);
-		}
-
-		if ($cmd === 'quit')
-		{
-			fclose($this->SMTPConnect);
-		}
-
-		return true;
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * SMTP Authenticate
-	 *
-	 * @return boolean
-	 */
-	protected function SMTPAuthenticate()
-	{
-		if (! $this->SMTPAuth)
-		{
-			return true;
-		}
-
-		if ($this->SMTPUser === '' && $this->SMTPPass === '')
-		{
-				throw FrameworkExceptionException::forNoSMTPAuth();
-		}
-
-		$this->sendData('AUTH LOGIN');
-		$reply = $this->getSMTPData();
-
-		if (strpos($reply, '503') === 0)    // Already authenticated
-		{
-			return true;
-		}
-		elseif (strpos($reply, '334') !== 0)
-		{
-				throw FrameworkExceptionException::forFailedSMTPLogin($reply);
-		}
-
-		$this->sendData(base64_encode($this->SMTPUser));
-		$reply = $this->getSMTPData();
-
-		if (strpos($reply, '334') !== 0)
-		{
-				throw FrameworkExceptionException::forSMTPAuthUsername($reply);
-		}
-
-		$this->sendData(base64_encode($this->SMTPPass));
-		$reply = $this->getSMTPData();
-
-		if (strpos($reply, '235') !== 0)
-		{
-				throw FrameworkExceptionException::forSMTPAuthPassword($reply);
-		}
-
-		if ($this->SMTPKeepAlive)
-		{
-			$this->SMTPAuth = false;
-		}
-
-		return true;
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Send SMTP data
-	 *
-	 * @param string $data
-	 *
-	 * @return boolean
-	 */
-	protected function sendData($data)
-	{
-		$data .= $this->newline;
-		for ($written = $timestamp = 0, $length = static::strlen($data); $written < $length; $written += $result)
-		{
-			if (($result = fwrite($this->SMTPConnect, static::substr($data, $written))) === false)
-			{
-				break;
-			}
-			// See https://bugs.php.net/bug.php?id=39598 and http://php.net/manual/en/function.fwrite.php#96951
-			elseif ($result === 0)
-			{
-				if ($timestamp === 0)
-				{
-					$timestamp = time();
-				}
-				elseif ($timestamp < (time() - $this->SMTPTimeout))
-				{
-					$result = false;
-					break;
-				}
-
-				usleep(250000);
-				continue;
-			}
-			else
-			{
-				$timestamp = 0;
-			}
-		}
-
-		if ($result === false)
-		{
-				throw FrameworkExceptionException::forSMTPDataFailure($data);
-		}
-
-		return true;
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Get SMTP data
-	 *
-	 * @return string
-	 */
-	protected function getSMTPData()
-	{
-		$data = '';
-
-		while ($str = fgets($this->SMTPConnect, 512))
-		{
-			$data .= $str;
-
-			if ($str[3] === ' ')
-			{
-				break;
-			}
-		}
-
-		return $data;
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Get Hostname
-	 *
-	 * There are only two legal types of hostname - either a fully
-	 * qualified domain name (eg: "mail.example.com") or an IP literal
-	 * (eg: "[1.2.3.4]").
-	 *
-	 * @link https://tools.ietf.org/html/rfc5321#section-2.3.5
-	 * @link http://cbl.abuseat.org/namingproblems.html
-	 *
-	 * @return string
-	 */
-	protected function getHostname()
-	{
-		if (isset($_SERVER['SERVER_NAME']))
-		{
-			return $_SERVER['SERVER_NAME'];
-		}
-
-		return isset($_SERVER['SERVER_ADDR']) ? '[' . $_SERVER['SERVER_ADDR'] . ']' : '[127.0.0.1]';
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Get Debug Message
-	 *
-	 * @param array $include List of raw data chunks to include in the output
-	 *                       Valid options are: 'headers', 'subject', 'body'
-	 *
-	 * @return string
-	 */
-	public function printDebugger($include = ['headers', 'subject', 'body'])
-	{
-		$msg = implode('', $this->debugMessage);
-
-		// Determine which parts of our raw data needs to be printed
-		$raw_data                      = '';
-		is_array($include) || $include = [$include];
-
-		in_array('headers', $include, true) && $raw_data  = htmlspecialchars($this->headerStr) . "\n";
-		in_array('subject', $include, true) && $raw_data .= htmlspecialchars($this->subject) . "\n";
-		in_array('body', $include, true) && $raw_data    .= htmlspecialchars($this->finalBody);
-
-		return $msg . ($raw_data === '' ? '' : '<pre>' . $raw_data . '</pre>');
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Set Message
-	 *
-	 * @param string $msg
-	 */
-	protected function setErrorMessage($msg)
-	{
-		$this->debugMessage[] = $msg . '<br />';
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Mime Types
-	 *
-	 * @param string $ext
-	 *
-	 * @return string
-	 */
-	protected function mimeTypes($ext = '')
-	{
-		$mime = Mimes::guessTypeFromExtension(strtolower($ext));
-
-		return ! empty($mime) ? $mime : 'application/x-unknown-content-type';
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Get the Message ID
-	 *
-	 * @return string
-	 */
-	protected function getMessageID()
-	{
-		$from = str_replace(['>', '<'], '', $this->headers['Return-Path']);
-
-		return '<' . uniqid('', true) . strstr($from, '@') . '>';
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Get Mail Encoding
-	 *
-	 * @return string
-	 */
-	protected function getEncoding()
-	{
-		in_array($this->encoding, $this->bitDepths) || $this->encoding = '8bit';
-
-		foreach ($this->baseCharsets as $charset)
-		{
-			if (strpos($this->charset, $charset) === 0)
-			{
-				$this->encoding = '7bit';
-				break;
-			}
-		}
-
-		return $this->encoding;
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Get content type (text/html/attachment)
-	 *
-	 * @return string
-	 */
-	protected function getContentType()
-	{
-		if ($this->mailType === 'html')
-		{
-			return empty($this->attachments) ? 'html' : 'html-attach';
-		}
-		elseif ($this->mailType === 'text' && ! empty($this->attachments))
-		{
-			return 'plain-attach';
-		}
-		else
-		{
-			return 'plain';
-		}
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Mime message
-	 *
-	 * @return string
-	 */
-	protected function getMimeMessage()
-	{
-		return 'This is a multi-part message in MIME format.' . $this->newline . 'Your email application may not support this format.';
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Build alternative plain text message
-	 *
-	 * Provides the raw message for use in plain-text headers of
-	 * HTML-formatted emails.
-	 * If the user hasn't specified his own alternative message
-	 * it creates one by stripping the HTML
-	 *
-	 * @return string
-	 */
-	protected function getAltMessage()
-	{
-		if (! empty($this->altMessage))
-		{
-			return ($this->wordWrap) ? $this->wordWrap($this->altMessage, 76) : $this->altMessage;
-		}
-
-		$body = preg_match('/\<body.*?\>(.*)\<\/body\>/si', $this->body, $match) ? $match[1] : $this->body;
-		$body = str_replace("\t", '', preg_replace('#<!--(.*)--\>#', '', trim(strip_tags($body))));
-
-		for ($i = 20; $i >= 3; $i --)
-		{
-			$body = str_replace(str_repeat("\n", $i), "\n\n", $body);
-		}
-
-		// Reduce multiple spaces
-		$body = preg_replace('| +|', ' ', $body);
-
-		return ($this->wordWrap) ? $this->wordWrap($body, 76) : $body;
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Destructor
-	 */
-	public function __destruct()
-	{
-		is_resource($this->SMTPConnect) && $this->sendCommand('quit');
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Byte-safe strlen()
-	 *
-	 * @param string $str
-	 *
-	 * @return integer
-	 */
-	protected static function strlen($str)
-	{
-		return (static::$func_overload) ? mb_strlen($str, '8bit') : strlen($str);
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Byte-safe substr()
-	 *
-	 * @param string       $str
-	 * @param integer      $start
-	 * @param integer|null $length
-	 *
-	 * @return string
-	 */
-	protected static function substr($str, $start, $length = null)
-	{
-		if (static::$func_overload)
-		{
-			return mb_substr($str, $start, $length, '8bit');
-		}
-
-		return isset($length) ? substr($str, $start, $length) : substr($str, $start);
-	}
-
 }
diff --git a/system/Mailer/MailerInterface.php b/system/Mailer/MailerInterface.php
index ea05f5a9990c..3f5390ceddf6 100644
--- a/system/Mailer/MailerInterface.php
+++ b/system/Mailer/MailerInterface.php
@@ -11,10 +11,34 @@
 
 namespace CodeIgniter\Mailer;
 
+use Config\Mailer;
+
+/**
+ * Mailer Interface
+ *
+ * Defines the methods and types for a Mailer class to handle sending emails.
+ * It is highly recommended that any interface implementations extend
+ * \CodeIgniter\Mailer\Handlers\BaseHandler which fulfills most of these
+ * methods and provides a lot of additional email utility.
+ */
 interface MailerInterface
 {
 	/**
-	 * Sends an Email
+	 * Stores the Mailer config.
+	 *
+	 * @param Mailer $config
+	 */
+	public function __construct(Mailer $config);
+
+	/**
+	 * Whether this handler is supported on this system.
+	 *
+	 * @return boolean
+	 */
+	public function isSupported(): bool;
+
+	/**
+	 * Sends an Email.
 	 *
 	 * @param Email $email
 	 */

From f9e1b287ce18a6c877c1d84c6e42a3e989cd48af Mon Sep 17 00:00:00 2001
From: MGatner <mgatner@icloud.com>
Date: Thu, 3 Jun 2021 02:00:47 +0000
Subject: [PATCH 5/8] Implement Encode and Attachments; begin message
 composition

---
 app/Config/Mailer.php                      |  120 +-
 system/Config/Services.php                 |    2 +-
 system/Language/en/Mailer.php              |    1 +
 system/Mailer/Attachment.php               |  110 ++
 system/Mailer/Email.php                    |  149 ++
 system/Mailer/Encode.php                   |  307 ++++
 system/Mailer/Format.php                   |   22 +
 system/Mailer/Handlers/BaseHandler.php     |  232 ++-
 system/Mailer/Handlers/DummyHandler.php    |   17 +-
 system/Mailer/Handlers/MailHandler.php     | 1608 +-------------------
 system/Mailer/Handlers/SendmailHandler.php | 1586 +------------------
 11 files changed, 983 insertions(+), 3171 deletions(-)
 create mode 100644 system/Mailer/Attachment.php
 create mode 100644 system/Mailer/Encode.php
 create mode 100644 system/Mailer/Format.php

diff --git a/app/Config/Mailer.php b/app/Config/Mailer.php
index eb233465fcce..c88e8b2d94a8 100644
--- a/app/Config/Mailer.php
+++ b/app/Config/Mailer.php
@@ -2,10 +2,25 @@
 
 namespace Config;
 
+/**
+ * Mailer Config
+ *
+ * Configuration settings for using the Mailer classes.
+ * This file has four sections:
+ *  1. Email Settings: Default fallback values to apply to each Email
+ *  3. Spool Settings: Options for format and bulk handling
+ *  3. System Settings: Environment settings that affect email encoding
+ *  2. Handler Settings: Configurations specific to each handler
+ */
 class Mailer
 {
+	//--------------------------------------------------------------------
+	// Email Settings
+	//--------------------------------------------------------------------
+
 	/**
-	 * Default values to use for every email.
+	 * Default values to use for every email (still overriden by parameters).
+	 *
 	 * Valid keys:
 	 * - body, subject, from, to, cc, bcc, replyTo, returnPath, priority, date
 	 *
@@ -16,19 +31,36 @@ class Mailer
 	public $defaults = [];
 
 	/**
-	 * The name of the preferred handler to use.
-	 * Testing disables mail by default.
+	 * String to use for the User Agent header.
 	 *
 	 * @var string
 	 */
-	public $handler = ENVIRONMENT === 'testing' ? 'dummy' : 'mail';
+	public $userAgent = 'CodeIgniter';
+
+	//--------------------------------------------------------------------
+	// Spool Settings
+	//--------------------------------------------------------------------
 
 	/**
-	 * The User Agent to specify when sending.
+	 * Mail format, either 'text' or 'html'.
 	 *
 	 * @var string
 	 */
-	public $userAgent = 'CodeIgniter';
+	public $mailFormat = 'text';
+
+	/**
+	 * Enable word-wrap for text emails.
+	 *
+	 * @var boolean
+	 */
+	public $wordWrap = true;
+
+	/**
+	 * Character count to wrap at
+	 *
+	 * @var integer
+	 */
+	public $wrapChars = 76;
 
 	/**
 	 * Whether to send bulk BCC emails in batches.
@@ -44,17 +76,77 @@ class Mailer
 	 */
 	public $batchSize = 200;
 
+	//--------------------------------------------------------------------
+	// System Settings
+	//--------------------------------------------------------------------
+
+	/**
+	 * Character set (default: UTF-8).
+	 *
+	 * @var string
+	 */
+	public $charset = 'UTF-8';
+
+	/**
+	 * Mail encoding.
+	 *
+	 * @var string '8bit' or '7bit'
+	 */
+	public $encoding = '8bit';
+
+	/**
+	 * Newline character sequence.
+	 * Use "\r\n" to comply with RFC 822.
+	 *
+	 * @link http://www.ietf.org/rfc/rfc822.txt
+	 * @var  string "\r\n" or "\n"
+	 */
+	public $newline = "\r\n";
+
 	/**
-	 * System-specific criteria for handling encodings.
+	 * CRLF character sequence.
+	 *
+	 * RFC 2045 specifies that for 'quoted-printable' encoding,
+	 * "\r\n" must be used. However, it appears that some servers
+	 * (even on the receiving end) don't handle it properly and
+	 * switching to "\n", while improper, is the only solution
+	 * that seems to work for all environments.
 	 *
-	 * @see \CodeIgniter\Mailer\Encoder::__construct()
+	 * @link http://www.ietf.org/rfc/rfc822.txt
+	 * @var  string
+	 */
+	public $crlf = "\r\n";
+
+	//--------------------------------------------------------------------
+	// Handler Settings
+	//--------------------------------------------------------------------
+
+	/**
+	 * The name of the preferred handler to use.
+	 * Note: Email is disable during testing by the Dummy handler.
 	 *
-	 * @var array<string,string>
+	 * @var string
+	 */
+	public $handler = ENVIRONMENT === 'testing' ? 'dummy' : 'mail';
+
+	/**
+	 * @var array<string,mixed>
+	 */
+	public $sendmail = [
+		// The server path to Sendmail
+		'mailpath' => '/usr/sbin/sendmail',
+	];
+
+	/**
+	 * @var array<string,mixed>
 	 */
-	public $encoder = [
-		'charset'  => 'UTF-8',
-		'encoding' => '8bit',
-		'newline'  => "\r\n",
-		'crlf'     => "\r\n",
+	public $smtp = [
+		'hostname'  => '',
+		'username'  => '',
+		'password'  => '',
+		'port'      => 25,
+		'timeout'   => 5,
+		'keepalive' => false,
+		'encrypt'   => 'tls', // tls or ssl
 	];
 }
diff --git a/system/Config/Services.php b/system/Config/Services.php
index 8d24e40f185a..e20192cda744 100644
--- a/system/Config/Services.php
+++ b/system/Config/Services.php
@@ -390,7 +390,7 @@ public static function logger(bool $getShared = true)
     /**
      * The Mailer class sends emails from any of the available protocol handlers.
      *
-     * @param MailerConfig|null $config
+     * @param Mailer|null $config
      * @param boolean $getShared
      *
      * @return MailerInterface
diff --git a/system/Language/en/Mailer.php b/system/Language/en/Mailer.php
index 0605cf73ec6a..c4f8b0a1ec60 100644
--- a/system/Language/en/Mailer.php
+++ b/system/Language/en/Mailer.php
@@ -15,6 +15,7 @@
 	'invalidAddress'      => 'Invalid email address: {0}',
 	'noFrom'              => 'Cannot send mail with no "From" header.',
 	'noRecipients'        => 'You must include recipients: To, Cc, or Bcc',
+	'mimeMessage'         => 'This is a multi-part message in MIME format.{0}Your email application may not support this format.',
 
 /*
 	'mustBeArray'          => 'The email validation method must be passed an array.',
diff --git a/system/Mailer/Attachment.php b/system/Mailer/Attachment.php
new file mode 100644
index 000000000000..778c371c07a2
--- /dev/null
+++ b/system/Mailer/Attachment.php
@@ -0,0 +1,110 @@
+<?php
+
+/**
+ * This file is part of the CodeIgniter 4 framework.
+ *
+ * (c) CodeIgniter Foundation <admin@codeigniter.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace CodeIgniter\Mailer;
+
+use CodeIgniter\Files\Exceptions\FileNotFoundException;
+use CodeIgniter\Files\File;
+use RuntimeException;
+
+/**
+ * Attachment Class
+ *
+ * Represents a file attachment.
+ */
+class Attachment extends File
+{
+	/**
+	 * Whether the disposition should be 'inline' (versus 'attachment')
+	 *
+	 * @var bool
+	 */
+	protected $inline;
+
+	/**
+	 * The name to use when sending the file. Defaults to the basename.
+	 *
+	 * @var string
+	 */
+	protected $name;
+
+	/**
+	 * The current ID to link to this attachment.
+	 * E.g. for inline pictures.
+	 *
+	 * @var string|null
+	 */
+	protected $contentId;
+
+	/**
+	 * Verifies local files and stores the values.
+	 *
+	 * @param string $path
+	 * @param bool $inline      Whether the disposition should be 'inline' (versus 'attachment')
+	 * @param string|null $name An alternate name to use
+	 *
+	 * @throws FileNotFoundException
+	 */
+	public function __construct(string $path, bool $inline = false, string $name = null)
+	{
+		parent::__construct($path, strpos($path, '://') === false);
+
+		$this->inline = $inline;
+		$this->name   = $name ?? $this->getFilename();
+	}
+
+	/**
+	 * Whether this Attachment has a Content-ID set.
+	 *
+	 * @return boolean
+	 */
+	public function hasContentId(): bool
+	{
+		return isset($this->contentId);
+	}
+
+	/**
+	 * Creates and returns a Content-ID
+	 * E.g. for inline pictures.
+	 *
+	 * @param string $filename
+	 *
+	 * @return string|boolean
+	 */
+	public function getContentId()
+	{
+		if (is_null($this->contentId))
+		{
+			$this->contentId = uniqid($this->name . '@', true);
+		}
+
+		return $this->contentId;
+	}
+
+	/**
+	 * Returns the file content ready for spooling.
+	 *
+	 * @return string
+	 *
+	 * @throws RuntimeException For open/access errors
+	 */
+	public function getContent(): bool
+	{
+		// Read in the binary data
+		$file = $this->openFile('rb');
+		$file->rewind();
+
+		$content = $file->fread($file->getSize());
+		unset($file);		
+
+		return chunk_split(base64_encode($content));
+	}
+}
diff --git a/system/Mailer/Email.php b/system/Mailer/Email.php
index 0b74f51adab4..eeda990c2553 100644
--- a/system/Mailer/Email.php
+++ b/system/Mailer/Email.php
@@ -24,6 +24,9 @@
  */
 class Email extends Message
 {
+	/**
+	 * Array of priorities and their encoded value.
+	 */
 	private const PRIORITIES = [
 		1 => '1 (Highest)',
 		2 => '2 (High)',
@@ -32,6 +35,18 @@ class Email extends Message
 		5 => '5 (Lowest)',
 	];
 
+	/**
+	 * Array of Headers to collapse into a CSV.
+	 */
+	private const CSV_HEADERS = ['To', 'Cc', 'Bcc'];
+
+	/**
+	 * Attachments to this email
+	 *
+	 * @var Attachment[]
+	 */
+	protected $attachements = [];
+
 	/**
 	 * This email's unique Message ID.
 	 *
@@ -39,6 +54,13 @@ class Email extends Message
 	 */
 	private $messageId;
 
+	/**
+	 * Boundaries for header & body divisions.
+	 *
+	 * @var array<string,string>
+	 */
+	private $boundaries = [];
+
 	/**
 	 * Stores any initial values.
 	 *
@@ -57,6 +79,8 @@ public function __clone()
 		unset($this->messageId);
 	}
 
+	//--------------------------------------------------------------------
+	// Class Operations
 	//--------------------------------------------------------------------
 
 	/**
@@ -93,6 +117,54 @@ public function set(array $data, bool $overwrite = true): self
 				}
 			}
 		}
+
+		return $this;
+	}
+
+	/**
+	 * Compiles headers into a spool-ready string.
+	 *
+	 * @param string $newline        Character(s) to use when combining the sequence
+	 * @param string[]|null $exclude An array of header names to exclude
+	 * @param string[]|null $include An array of header names to include
+	 *
+	 * @return string
+	 */
+	public function getHeaderString(string $newline = "\r\n", array $exclude = null, array $include = null): string
+	{
+		$string = '';
+
+		// Use $headers directly instead of headers() so as not to trigger populateHeaders()
+		foreach ($this->headers as $name => $value)
+		{
+			// Check exclusion
+			if (isset($exclude) && in_array($name, $exclude))
+			{
+				continue;
+			}
+			// Check includion
+			if (isset($include) && ! in_array($name, $include))
+			{
+				continue;
+			}
+
+			// Check for a collapsible
+			if (in_array($name, self::CSV_HEADERS) && is_array($value))
+			{
+				$string .= implode(',', array_map('__toString', $value));
+			}
+			elseif (is_array($value))
+			{
+				foreach ($value as $header)
+				{
+					$string .= $header . $this->newline;
+				}
+			}
+			else
+			{
+				$string .= $value . $this->newline; // Trailing newline is intentional
+			}
+		}
 	}
 
 	//--------------------------------------------------------------------
@@ -330,6 +402,83 @@ public function getMessageId(): ?string
 		return $this->messageId;
 	}
 
+	/**
+	 * Tracks boundary keys so they can be reused.
+	 *
+	 * @return string
+	 */
+	public function getBoundary(string $name): string
+	{
+		if (! isset($this->boundaries[$name]))
+		{
+			$this->boundaries[$name] = uniqid($name . '_', true);
+		}
+
+		return $this->boundaries[$name];
+	}
+
+	//--------------------------------------------------------------------
+	// Attachments
+	//--------------------------------------------------------------------
+
+	/**
+	 * Adds an Attachment.
+	 *
+	 * @param Attachment $attachment
+	 *
+	 * @return $this
+	 */
+	public function attach(Attachment $attachment): self
+	{
+		$this->attachments[] = $attachment;
+
+		return $this;
+	}
+
+	/**
+	 * Returns all or filtered Attachments.
+	 *
+	 * @param bool|null $contentFilter (Optional) Whether to include/exclude attachments with Content ID
+	 *
+	 * @return Attachment[]
+	 */
+	public function getAttachments(bool $contentFilter = null): array
+	{
+		if (is_null($contentFilter))
+		{
+			return $this->attachments;
+		}
+
+		$attachments = [];
+		foreach ($this->attachments as $attachment)
+		{
+			if ($contentFilter && $attachment->hasContentId())
+			{
+				$attachments[] = $attachment;
+			}
+			if (! $contentFilter && ! $attachment->hasContentId())
+			{
+				$attachments[] = $attachment;
+			}
+		}
+
+		return $attachments;
+	}
+
+	/**
+	 * Removes and returns all Attachments.
+	 *
+	 * @return Attachment[]
+	 */
+	public function detach(): array
+	{
+		$attachments = $this->getAttachments();
+
+		$this->attachments = [];
+
+		return $attachments;
+	}
+
 	//--------------------------------------------------------------------
 	// Backwards Compatibility
 	//--------------------------------------------------------------------
diff --git a/system/Mailer/Encode.php b/system/Mailer/Encode.php
new file mode 100644
index 000000000000..03fe697d4725
--- /dev/null
+++ b/system/Mailer/Encode.php
@@ -0,0 +1,307 @@
+<?php
+
+/**
+ * This file is part of the CodeIgniter 4 framework.
+ *
+ * (c) CodeIgniter Foundation <admin@codeigniter.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace CodeIgniter\Mailer;
+
+use Config\Mailer;
+
+/**
+ * Mailer Encode Class
+ *
+ * Handles the encoding of various portions of
+ * an email into all their possible forms.
+ *
+ * @property-read string $charset
+ * @property-read string $encoding
+ * @property-read string $newline
+ * @property-read string $crlf
+ */
+final class Encode
+{
+	/**
+	 * Valid newline characters.
+	 */
+	private const NEWLINES = [
+		"\r\n",
+		"\r",
+		"\n",
+	];
+
+	/**
+	 * Valid mail encodings
+	 */
+	private const ENCODINGS = [
+		'7bit',
+		'8bit',
+	];
+
+	/**
+	 * Character sets valid for 7-bit encoding, excluding language suffix.
+	 */
+	private const CHARSETS = [
+		'us-ascii',
+		'iso-2022-',
+	];
+
+	/**
+	 * ASCII code numbers for "safe" characters that can always be used literally,
+	 * without encoding, as described in RFC 2049.
+	 *
+	 * @link http://www.ietf.org/rfc/rfc2049.txt
+	 */
+	private const ASCII_SAFE = [
+		// ' (  )   +   ,   -   .   /   :   =   ?
+		39, 40, 41, 43, 44, 45, 46, 47, 58, 61, 63,
+		// digits
+		48, 49, 50, 51, 52, 53, 54, 55, 56, 57,
+		// upper-case letters
+		65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90,
+		// lower-case letters
+		97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122,
+	];
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Character set.
+	 *
+	 * @var string
+	 */
+	private $charset;
+
+	/**
+	 * Mail encoding
+	 *
+	 * @var string
+	 */
+	private $encoding;
+
+	/**
+	 * Newline character sequence.
+	 *
+	 * @link http://www.ietf.org/rfc/rfc822.txt
+	 * @var string
+	 */
+	private $newline;
+
+	/**
+	 * CRLF character sequence
+	 *
+	 * @link http://www.ietf.org/rfc/rfc822.txt
+	 * @var string
+	 */
+	private $crlf;
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Validates and stores config values.
+	 *
+	 * @param Mailer $config
+	 */
+	public function __construct(Mailer $config)
+	{
+		// Make sure charset is the correct case
+		$this->charset = strtoupper($config->charset);
+
+		// Validate newline values
+		$this->newline = in_array($config->newline, self::NEWLINES, true) ? $config->newline : "\r\n";
+		$this->crlf    = in_array($config->crlf, ["\r\n", "\r", "\n"], true) ? $config->crlf : "\r\n";
+
+		// Check for charsets that need 7bit
+		foreach (self::CHARSETS as $charset)
+		{
+			if (strpos($this->charset, $charset) === 0)
+			{
+				$this->encoding = '7bit';
+				break;
+			}
+		}
+
+		// Validate encoding
+		$this->encoding = in_array($config->encoding, self::ENCODINGS, true) ? $config->encoding : '8bit';
+	}
+
+	/**
+	 * Allows access to the stored, validated properties.
+	 *
+	 * @param string $name
+	 *
+	 * @return string
+	 */
+	public function __get(string $name): string
+	{
+		return $this->$name;
+	}
+
+	//--------------------------------------------------------------------
+
+	/**
+	 * Encodes the name portion of an Address, applying Q encoding
+	 * if necessary, or escaping unsafe characters otherwise
+	 *
+	 * @param Address $address
+	 *
+	 * @return Address
+	 */
+	public function address(Address $address): Address
+	{
+		// The email has already been verified so encoding only applies to the display name
+		if (empty($address->getName()))
+		{
+			return $address;
+		}
+
+		$name = $address->getName();
+
+		// Use Q encoding if there are any characters that require it
+		if (preg_match('/[\200-\377]/', $name))
+		{
+			$name = $this->Q($name);
+		}
+		// Otherwise, escape non-printing characters, slashes, and double quotes
+		else
+		{
+			$name = addcslashes($name, "\0..\37\177'\"\\");
+		}
+
+		return new Address($address->getEmail(), $name);
+	}
+
+	/**
+	 * Performs "Q Encoding" on a string for use in email headers.
+	 * This is mostly straight from CodeIgniter 3.
+	 *
+	 * @see https://www.freesoft.org/CIE/RFC/1522/6.htm
+	 *
+	 * @param string $string
+	 *
+	 * @return string
+	 */
+	public function Q(string $string): string
+	{
+		$string = str_replace(["\r", "\n"], '', $string);
+		$output = '=?' . $this->charset . '?Q?';
+		$chars  = $this->charset === 'UTF-8' ? mb_strlen($string, 'UTF-8') : mb_strlen($string, '8bit');
+		$length = mb_strlen($output, '8bit');
+
+		for ($i = 0; $i < $chars; $i++)
+		{
+			$chr = ($this->charset === 'UTF-8' && extension_loaded('iconv'))
+				? '=' . implode('=', str_split(strtoupper(bin2hex(iconv_substr($string, $i, 1, $this->charset))), 2))
+				: '=' . strtoupper(bin2hex($string[$i]));
+
+			$chrlen = mb_strlen($chr, '8bit');
+
+			// RFC 2045 sets a limit of 76 characters per line, but leave space for ?= at the end of each line
+			if ($length + $chrlen > 74)
+			{
+				$output .= '?=' . $this->crlf // EOL
+					. ' =?' . $this->charset . '?Q?' . $chr; // New line
+
+				$length = 6 + mb_strlen($this->charset, '8bit') + $chrlen; // Reset the length for the new line
+			}
+			else
+			{
+				$output .= $chr;
+				$length += $chrlen;
+			}
+		}
+
+		// End the header
+		return $output . '?=';
+	}
+	/**
+	 * Prepares a string for Quoted-Printable Content-Transfer-Encoding
+	 * Refer to RFC 2045 http://www.ietf.org/rfc/rfc2045.txt
+	 *
+	 * @param string $str
+	 *
+	 * @return string
+	 */
+	public function quotedPrintable(string $str): string
+	{
+		// RFC 2045 specifies CRLF as "\r\n".
+		// However, many developers choose to override that and violate
+		// the RFC rules due to (apparently) a bug in MS Exchange,
+		// which only works with "\n".
+		if ($this->crlf === "\r\n")
+		{
+			return quoted_printable_encode($str);
+		}
+
+		// Reduce multiple spaces & remove nulls
+		$str = preg_replace(['| +|', '/\x00+/'], [' ', ''], $str);
+
+		// Standardize newlines
+		if (strpos($str, "\r") !== false)
+		{
+			$str = str_replace(["\r\n", "\r"], "\n", $str);
+		}
+
+		$escape = '=';
+		$output = '';
+
+		foreach (explode("\n", $str) as $line)
+		{
+			$length = mb_strlen($line);
+			$temp   = '';
+
+			// Loop through each character in the line to add soft-wrap
+			// characters at the end of a line " =\r\n" and add the newly
+			// processed line(s) to the output (see comment on $crlf class property)
+			for ($i = 0; $i < $length; $i ++)
+			{
+				// Grab the next character
+				$char  = $line[$i];
+				$ascii = ord($char);
+
+				// Convert spaces and tabs but only if it's the end of the line
+				if ($ascii === 32 || $ascii === 9)
+				{
+					if ($i === ($length - 1))
+					{
+						$char = $escape . sprintf('%02s', dechex($ascii));
+					}
+				}
+				// DO NOT move this below the self::ASCII_SAFE line!
+				//
+				// = (equals) signs are allowed by RFC2049, but must be encoded
+				// as they are the encoding delimiter!
+				elseif ($ascii === 61)
+				{
+					$char = $escape . strtoupper(sprintf('%02s', dechex($ascii)));  // =3D
+				}
+				elseif (! in_array($ascii, self::ASCII_SAFE, true))
+				{
+					$char = $escape . strtoupper(sprintf('%02s', dechex($ascii)));
+				}
+
+				// If we're at the character limit, add the line to the output,
+				// reset our temp variable, and keep on chuggin'
+				if ((mb_strlen($temp) + mb_strlen($char)) >= 76)
+				{
+					$output .= $temp . $escape . $this->crlf;
+					$temp    = '';
+				}
+
+				// Add the character to our temporary line
+				$temp .= $char;
+			}
+
+			// Add our completed line to the output
+			$output .= $temp . $this->crlf;
+		}
+
+		// get rid of extra CRLF tacked onto the end
+		return mb_substr($output, 0, mb_strlen($this->crlf) * -1);
+	}
+}
diff --git a/system/Mailer/Format.php b/system/Mailer/Format.php
new file mode 100644
index 000000000000..2d16dd02bd3b
--- /dev/null
+++ b/system/Mailer/Format.php
@@ -0,0 +1,22 @@
+<?php
+
+/**
+ * This file is part of the CodeIgniter 4 framework.
+ *
+ * (c) CodeIgniter Foundation <admin@codeigniter.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace CodeIgniter\Mailer;
+
+/**
+ * Mailer Format Class
+ *
+ * Handles the encoding of various portions of
+ * an email into all their possible forms.
+ */
+final class Format
+{
+}
diff --git a/system/Mailer/Handlers/BaseHandler.php b/system/Mailer/Handlers/BaseHandler.php
index 54072206309a..82b090ac0b87 100644
--- a/system/Mailer/Handlers/BaseHandler.php
+++ b/system/Mailer/Handlers/BaseHandler.php
@@ -14,6 +14,7 @@
 use CodeIgniter\Events\Events;
 use CodeIgniter\Mailer\Email;
 use CodeIgniter\Mailer\Exceptions\MailerException;
+use CodeIgniter\Mailer\MailerInterface;
 use Config\Mailer;
 
 /**
@@ -23,6 +24,14 @@
  */
 abstract class BaseHandler implements MailerInterface
 {
+	/**
+	 * Protocol for this handler.
+	 * Set by child classes.
+	 *
+	 * @var string
+	 */
+	protected $protocol;
+
 	/**
 	 * The Mailer config.
 	 *
@@ -31,19 +40,18 @@ abstract class BaseHandler implements MailerInterface
 	protected $config;
 
 	/**
-	 * The config-specific Encoder.
+	 * The config-specific Encode instance.
 	 *
-	 * @var Encoder
+	 * @var Encode
 	 */
-	protected $encoder;
+	protected $encode;
 
 	/**
-	 * Protocol for this handler.
-	 * Set by child classes.
+	 * The config-specific Format instance.
 	 *
-	 * @var string
+	 * @var Format
 	 */
-	protected $protocol;
+	protected $format;
 
 	//--------------------------------------------------------------------
 
@@ -66,14 +74,22 @@ abstract protected function spool(Email $email);
 	//--------------------------------------------------------------------
 
 	/**
-	 * Stores the Mailer config.
+	 * Stores the Mailer config and preps encoding and formatting.
 	 *
 	 * @param Mailer $config
 	 */
 	public function __construct(Mailer $config)
 	{
-		$this->config  = clone $config;
-		$this->encoder = new Encoder($this->config->encoder);
+		helper(['text']);
+
+		$this->config = clone $config;
+		$this->encode = new Encode($this->config);
+		$this->format = new Format($this->config);
+
+		// Enforce a few config validations
+		$this->config->format    = in_array($this->config->format, ['html', 'text']) ? $this->config->format : 'text';
+		$this->config->wordWrap  = is_bool($this->config->wordWrap) ? $this->config->wordWrap : true;
+		$this->config->wrapChars = is_int($this->config->wrapChars) ? $this->config->wrapChars : 76;
 	}
 
 	/**
@@ -136,8 +152,7 @@ public function send(Email $email)
 
 		$result = $this->spool($email);
 
-
-
+/* WIP
 		if ($result)
 		{
 			$this->setArchiveValues();
@@ -149,9 +164,8 @@ public function send(Email $email)
 
 			Events::trigger('email_sent', $email);
 		}
-
+*/
 		return $result;
-
 	}
 
 	/**
@@ -193,9 +207,197 @@ protected function buildHeaders(Email $email): self
 		$email->setHeader('User-Agent', $this->config->userAgent);
 		$email->setHeader('X-Mailer', $this->config->userAgent);
 		$email->setHeader('X-Sender', $email->getFrom()->getEmail());
-		$email->setHeader('Message-ID', $this->getMessageID());
+		$email->setHeader('Message-ID', $email->getMessageID());
 		$email->setHeader('Mime-Version', '1.0');
 
+		// Content headers take a bit more calculating
+		$this->buildContentHeaders($email);
+
 		return $this;
 	}
+
+	/**
+	 * Caculates and sets the Headers for Content-Type and Content-Transfer-Encoding.
+	 *
+	 * @param Email
+	 *
+	 * @return $this
+	 */
+	protected function buildContentHeaders(Email $email): self
+	{
+		// If there are no attachments this is much easier
+		if ($email->getAttachments() === [])
+		{
+			// text
+			if ($this->config->mailFormat == 'text')
+			{
+				$email->setHeader('Content-Type', 'text/plain; charset=' . $this->encode->charset);
+				$email->setHeader('Content-Transfer-Encoding', 'text/plain; charset=' . $this->encode->charset);
+
+				return $this;
+			}
+
+			/**
+			 * Version 3 edition supported forced multipart messages for html format despite
+			 * it not being in the configuration or documentation. Should this feature need
+			 * to be added back then this is the appropriate place.
+			 */
+
+			// html
+			$email->setHeader('Content-Type', 'text/html; charset=' . $this->encode->charset);
+			$email->setHeader('Content-Transfer-Encoding', 'quoted-printable');
+
+			return $this;
+		}
+
+		// text + attachments
+		if ($this->config->mailFormat == 'text')
+		{
+			$email->setHeader('Content-Type', 'multipart/mixed; boundary=' . $email->getBoundary('B_ATC'));
+
+			return $this;
+		}
+
+		// html + attachments
+		if ($email->getAttachments(false))
+		{
+			$email->setHeader('Content-Type', 'multipart/mixed; boundary=' . $email->getBoundary('B_ATC'));
+		}
+		if ($email->getAttachments(true))
+		{
+			$email->setHeader('Content-Type', 'multipart/related; boundary=' . $email->getBoundary('B_REL'));
+		}
+	}
+
+	/**
+	 * Returns the string version of the Headers from the email.
+	 * Split out for handlers that need to skip the subject.
+	 *
+	 * @param Email
+	 *
+	 * @return string
+	 */
+	protected function getHeaderString(Email $email): string
+	{
+		return $email->getHeaderString($this->config->newline);
+	}
+
+	/**
+	 * Returns the string version of the message, including all headers and attachments.
+	 *
+	 * @param Email
+	 *
+	 * @return string
+	 */
+	protected function getMessageString(Email $email): string
+	{
+		$message = '';
+
+		// If there are no attachments this is much easier
+		if ($email->getAttachments() === [])
+		{
+			// text
+			if ($this->config->format == 'text')
+			{
+				$message .= $email->getHeaderString($this->config->newline, null, ['Content-Type', 'Content-Transfer-Encoding']);
+				$message .= $this->config->newline . $this->config->newline;
+				$message .= $this->config->wordWrap ? word_wrap($email->getBody()) : $email->getBody();
+
+				return $message;
+			}
+
+			// html
+			$message .= $email->getHeaderString($this->config->newline, null, ['Content-Type', 'Content-Transfer-Encoding']);
+			$message .= $this->config->newline . $this->config->newline;
+			$message .= $this->encode->quotedPrintable($email->getBody()) . $this->config->newline . $this->config->newline;
+
+			return $message;
+		}
+
+		// text + attachment
+		if ($this->config->format == 'text')
+		{
+			$message .= $email->getHeaderString($this->config->newline, null, ['Content-Type']);
+			$message .= $this->config->newline . $this->config->newline;
+
+			$message .= lang('Mailer.mimeMessage', [$this->config->newline])
+					. $this->config->newline . $this->config->newline
+					. '--' . $email->getBoundary('B_ATC') . $this->config->newline
+					. 'Content-Type: text/plain; charset=' . $this->encode->charset . $this->config->newline
+					. 'Content-Transfer-Encoding: ' . $this->encode->encoding . $this->config->newline
+					. $this->config->newline
+					. $email->getBody() . $this->config->newline . $this->config->newline;
+
+			$this->appendAttachments($body, $boundary);
+
+			return $message;
+		}
+
+		// html + attachments
+
+/* WIP
+		$alt_boundary  = uniqid('B_ALT_', true);
+		$last_boundary = null;
+
+		if ($this->attachmentsHaveMultipart('mixed'))
+		{
+			$atc_boundary  = uniqid('B_ATC_', true);
+			$hdr          .= 'Content-Type: multipart/mixed; boundary="' . $atc_boundary . '"';
+			$last_boundary = $atc_boundary;
+		}
+
+		if ($this->attachmentsHaveMultipart('related'))
+		{
+			$rel_boundary        = uniqid('B_REL_', true);
+			$rel_boundary_header = 'Content-Type: multipart/related; boundary="' . $rel_boundary . '"';
+
+			if (isset($last_boundary))
+			{
+				$body .= '--' . $last_boundary . $this->newline . $rel_boundary_header;
+			}
+			else
+			{
+				$hdr .= $rel_boundary_header;
+			}
+
+			$last_boundary = $rel_boundary;
+		}
+
+		if ($this->getProtocol() === 'mail')
+		{
+			$this->headerStr .= $hdr;
+		}
+
+		static::strlen($body) && $body .= $this->newline . $this->newline;
+		$body                          .= $this->getMimeMessage() . $this->newline . $this->newline
+				. '--' . $last_boundary . $this->newline
+				. 'Content-Type: multipart/alternative; boundary="' . $alt_boundary . '"' . $this->newline . $this->newline
+				. '--' . $alt_boundary . $this->newline
+				. 'Content-Type: text/plain; charset=' . $this->charset . $this->newline
+				. 'Content-Transfer-Encoding: ' . $this->getEncoding() . $this->newline . $this->newline
+				. $this->getAltMessage() . $this->newline . $this->newline
+				. '--' . $alt_boundary . $this->newline
+				. 'Content-Type: text/html; charset=' . $this->charset . $this->newline
+				. 'Content-Transfer-Encoding: quoted-printable' . $this->newline . $this->newline
+				. $this->prepQuotedPrintable($this->body) . $this->newline . $this->newline
+				. '--' . $alt_boundary . '--' . $this->newline . $this->newline;
+
+		if (! empty($rel_boundary))
+		{
+			$body .= $this->newline . $this->newline;
+			$this->appendAttachments($body, $rel_boundary, 'related');
+		}
+
+		// multipart/mixed attachments
+		if (! empty($atc_boundary))
+		{
+			$body .= $this->newline . $this->newline;
+			$this->appendAttachments($body, $atc_boundary, 'mixed');
+		}
+
+		break;
+*/
+
+		return $message;
+	}
 }
diff --git a/system/Mailer/Handlers/DummyHandler.php b/system/Mailer/Handlers/DummyHandler.php
index e5fb348ea6bd..3d879f16d9db 100644
--- a/system/Mailer/Handlers/DummyHandler.php
+++ b/system/Mailer/Handlers/DummyHandler.php
@@ -12,24 +12,27 @@
 namespace CodeIgniter\Mailer\Handlers;
 
 use CodeIgniter\Mailer\Email;
-use CodeIgniter\Mailer\MailerInterface;
-use Config\Mailer;
 
-class DummyHandler implements MailerInterface
+class DummyHandler extends BaseHandler
 {
 	/**
-	 * @param Mailer $config
+	 * Whether this handler is supported on this system.
+	 *
+	 * @return boolean
 	 */
-	public function __construct(Mailer $config)
+	public function isSupported(): bool
 	{
+		return true;
 	}
 
 	/**
-	 * Does not send an Email
+	 * Does not spools an Email to the server.
 	 *
 	 * @param Email $email
+	 *
+	 * @return boolean
 	 */
-	public function send(Email $email)
+	protected function spool(Email $email)
 	{
 	}
 }
diff --git a/system/Mailer/Handlers/MailHandler.php b/system/Mailer/Handlers/MailHandler.php
index 1a9421b8772d..5aa6a99d7e3b 100644
--- a/system/Mailer/Handlers/MailHandler.php
+++ b/system/Mailer/Handlers/MailHandler.php
@@ -1,1634 +1,116 @@
 <?php
-namespace CodeIgniter\Mailer\Handlers;
 
 /**
- * CodeIgniter
- *
- * An open source application development framework for PHP
- *
- * This content is released under the MIT License (MIT)
- *
- * Copyright (c) 2014 - 2018, British Columbia Institute of Technology
+ * This file is part of the CodeIgniter 4 framework.
  *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
+ * (c) CodeIgniter Foundation <admin@codeigniter.com>
  *
- * The above copyright notice and this permission notice shall be included in
- * all copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
- * THE SOFTWARE.
- *
- * @package    CodeIgniter
- * @author     EllisLab Dev Team
- * @copyright  Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright  Copyright (c) 2014 - 2018, British Columbia Institute of Technology (http://bcit.ca/)
- * @license    http://opensource.org/licenses/MIT    MIT License
- * @link       https://codeigniter.com
- * @since      Version 1.0.0
- * @filesource
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
  */
 
+namespace CodeIgniter\Mailer\Handlers;
+
 use CodeIgniter\Mailer\Email;
 use CodeIgniter\Mailer\Exceptions\MailerException;
 use Config\Mimes;
 use Psr\Log\LoggerAwareTrait;
 
 /**
- * CodeIgniter Mailer Class
+ * Mail Handler
  *
- * Permits email to be sent using Mail, Sendmail, or SMTP.
- *
- * @package    CodeIgniter
- * @subpackage Libraries
- * @category   Libraries
- * @author     EllisLab Dev Team
- * @link       https://codeigniter.com/user_guide/libraries/email.html
+ * Handles sending email using the PHP mail() function.
  */
 class MailHandler extends BaseHandler
 {
-
-	/**
-	 * Message format.
-	 *
-	 * @var string 'text' or 'html'
-	 */
-	public $mailType = 'text';
-
-	/**
-	 * Character set (default: utf-8)
-	 *
-	 * @var string
-	 */
-	public $charset = 'utf-8';
-
-	/**
-	 * Alternative message (for HTML messages only)
-	 *
-	 * @var string
-	 */
-	public $altMessage = '';
-
-	/**
-	 * Whether to validate e-mail addresses.
-	 *
-	 * @var boolean
-	 */
-	public $validate = true;
-
-	/**
-	 * X-Priority header value.
-	 *
-	 * @var integer 1-5
-	 */
-	public $priority = 3;            // Default priority (1 - 5)
-
-	/**
-	 * Newline character sequence.
-	 * Use "\r\n" to comply with RFC 822.
-	 *
-	 * @link http://www.ietf.org/rfc/rfc822.txt
-	 * @var  string "\r\n" or "\n"
-	 */
-	public $newline = "\n";            // Default newline. "\r\n" or "\n" (Use "\r\n" to comply with RFC 822)
-
-	/**
-	 * CRLF character sequence
-	 *
-	 * RFC 2045 specifies that for 'quoted-printable' encoding,
-	 * "\r\n" must be used. However, it appears that some servers
-	 * (even on the receiving end) don't handle it properly and
-	 * switching to "\n", while improper, is the only solution
-	 * that seems to work for all environments.
-	 *
-	 * @link http://www.ietf.org/rfc/rfc822.txt
-	 * @var  string
-	 */
-	public $CRLF = "\n";
-
-	/**
-	 * Whether to use Delivery Status Notification.
-	 *
-	 * @var boolean
-	 */
-	public $DSN = false;
-
-	/**
-	 * Whether to send multipart alternatives.
-	 * Yahoo! doesn't seem to like these.
-	 *
-	 * @var boolean
-	 */
-	public $sendMultipart = true;
-
-	/**
-	 * Whether to send messages to BCC recipients in batches.
-	 *
-	 * @var boolean
-	 */
-	public $BCCBatchMode = false;
-
-	/**
-	 * BCC Batch max number size.
-	 *
-	 * @see self::$BCCBatchMode
-	 * @var integer
-	 */
-	public $BCCBatchSize = 200;
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Subject header
-	 *
-	 * @var string
-	 */
-	protected $subject = '';
-
 	/**
-	 * Message body
+	 * Protocol for this handler.
 	 *
 	 * @var string
 	 */
-	protected $body = '';
-
-	/**
-	 * Final message body to be sent.
-	 *
-	 * @var string
-	 */
-	protected $finalBody = '';
-
-	/**
-	 * Final headers to send
-	 *
-	 * @var string
-	 */
-	protected $headerStr = '';
-
-	/**
-	 * SMTP Connection socket placeholder
-	 *
-	 * @var resource
-	 */
-	protected $SMTPConnect = '';
-
-	/**
-	 * Mail encoding
-	 *
-	 * @var string '8bit' or '7bit'
-	 */
-	protected $encoding = '8bit';
-
-	/**
-	 * Whether to send a Reply-To header
-	 *
-	 * @var boolean
-	 */
-	protected $replyToFlag = false;
-
-	/**
-	 * Debug messages
-	 *
-	 * @see self::printDebugger()
-	 * @var array
-	 */
-	protected $debugMessage = [];
-
-	/**
-	 * Recipients
-	 *
-	 * @var array
-	 */
-	protected $recipients = [];
-
-	/**
-	 * CC Recipients
-	 *
-	 * @var array
-	 */
-	protected $CCArray = [];
-
-	/**
-	 * BCC Recipients
-	 *
-	 * @var array
-	 */
-	protected $BCCArray = [];
-
-	/**
-	 * Message headers
-	 *
-	 * @var array
-	 */
-	protected $headers = [];
-
-	/**
-	 * Attachment data
-	 *
-	 * @var array
-	 */
-	protected $attachments = [];
-
-	/**
-	 * Valid $protocol values
-	 *
-	 * @see self::$protocol
-	 * @var array
-	 */
-	protected $protocols = [
-		'mail',
-		'sendmail',
-		'smtp',
-	];
-
-	/**
-	 * Base charsets
-	 *
-	 * Character sets valid for 7-bit encoding,
-	 * excluding language suffix.
-	 *
-	 * @var array
-	 */
-	protected $baseCharsets = [
-		'us-ascii',
-		'iso-2022-',
-	];
-
-	/**
-	 * Bit depths
-	 *
-	 * Valid mail encodings
-	 *
-	 * @see self::$encoding
-	 * @var array
-	 */
-	protected $bitDepths = [
-		'7bit',
-		'8bit',
-	];
-
-	/**
-	 * $priority translations
-	 *
-	 * Actual values to send with the X-Priority header
-	 *
-	 * @var array
-	 */
-	protected $priorities = [
-		1 => '1 (Highest)',
-		2 => '2 (High)',
-		3 => '3 (Normal)',
-		4 => '4 (Low)',
-		5 => '5 (Lowest)',
-	];
-
-	/**
-	 * mbstring.func_overload flag
-	 *
-	 * @var boolean
-	 */
-	protected static $func_overload;
-
-	/**
-	 * Logger instance to record error messages and awarnings.
-	 *
-	 * @var \PSR\Log\LoggerInterface
-	 */
-	protected $logger;
-
-	//--------------------------------------------------------------------
+	protected $protocol = 'mail';
 
 	/**
-	 * Constructor - Sets Preferences
-	 *
-	 * The constructor can be passed an array of config values
+	 * Whether this handler is supported on this system.
 	 *
-	 * @param array|null $config
+	 * @return boolean
 	 */
-	public function __construct($config = null)
+	public function isSupported(): bool
 	{
-		$this->protocol = 'mail';
-		$this->initialize($config);
-
-		log_message('info', 'Mailer Class Initialized');
+		return function_exists('mail');
 	}
 
-	//--------------------------------------------------------------------
-
 	/**
-	 * Initialize preferences
+	 * Returns the string version of the Headers from the email,
+	 * appending a newline and excluding 'Subject' (mail() handles it directly).
 	 *
-	 * @param array|\Config\Mailer $config
+	 * @param Email
 	 *
-	 * @return $this
+	 * @return string
 	 */
-	public function initialize($config)
+	protected function getHeaderString(Email $email): string
 	{
-		$this->clear();
-
-		if ($config instanceof \Config\Mailer)
-		{
-			$config = get_object_vars($config);
-		}
-
-		foreach (get_class_vars(get_class($this)) as $key => $value)
-		{
-			if (property_exists($this, $key) && isset($config[$key]))
-			{
-				$method = 'set' . ucfirst($key);
-
-				if (method_exists($this, $method))
-				{
-					$this->$method($config[$key]);
-				}
-			}
-		}
-
-		$this->charset  = strtoupper($this->charset);
-		$this->SMTPAuth = isset($this->SMTPUser[0], $this->SMTPPass[0]);
-
-		return $this;
+		return $email->getHeaderString($this->config->newline, ['Subject']) . $this->conifg->newline;
 	}
 
-	//--------------------------------------------------------------------
+/* WIP */
 
 	/**
-	 * Initialize the Data
+	 * Spools an Email to the server.
 	 *
-	 * @param boolean $clearAttachments
+	 * @param Email $email
 	 *
-	 * @return $this
-	 */
-	public function clear($clearAttachments = false)
-	{
-		$this->subject      = '';
-		$this->body         = '';
-		$this->finalBody    = '';
-		$this->headerStr    = '';
-		$this->replyToFlag  = false;
-		$this->recipients   = [];
-		$this->CCArray      = [];
-		$this->BCCArray     = [];
-		$this->headers      = [];
-		$this->debugMessage = [];
-
-		//      $this->setHeader('Date', $this->setDate());
-
-		if ($clearAttachments !== false)
-		{
-			$this->attachments = [];
-		}
-
-		return $this;
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Build final headers
-	 */
-	protected function buildHeaders()
-	{
-		$this->setHeader('User-Agent', $this->userAgent);
-		$this->setHeader('X-Sender', $this->cleanEmail($this->headers['From']));
-		$this->setHeader('X-Mailer', $this->userAgent);
-		$this->setHeader('X-Priority', $this->priorities[$this->priority]);
-		$this->setHeader('Message-ID', $this->getMessageID());
-		$this->setHeader('Mime-Version', '1.0');
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Write Headers as a string
+	 * @return boolean
 	 */
-	protected function writeHeaders()
+	protected function spool(Email $email)
 	{
-		if ($this->protocol === 'mail')
-		{
-			if (isset($this->headers['Subject']))
-			{
-				$this->subject = $this->headers['Subject'];
-				unset($this->headers['Subject']);
-			}
-		}
-
-		reset($this->headers);
-		$this->headerStr = '';
-
-		foreach ($this->headers as $key => $val)
-		{
-			$val = trim($val);
-
-			if ($val !== '')
-			{
-				$this->headerStr .= $key . ': ' . $val . $this->newline;
-			}
-		}
+		$this->unwrapSpecials();
 
-		if ($this->getProtocol() === 'mail')
+		try
 		{
-			$this->headerStr = rtrim($this->headerStr);
+			$success = $this->sendWithMail();
 		}
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Build Final Body and attachments
-	 */
-	protected function buildMessage()
-	{
-		if ($this->wordWrap === true && $this->mailType !== 'html')
+		catch (\ErrorException $e)
 		{
-			$this->body = $this->wordWrap($this->body);
+			$success = false;
+			$this->logger->error('Mailer: ' . $method . ' throwed ' . $e->getMessage());
 		}
 
-		$this->writeHeaders();
-
-		$hdr  = ($this->getProtocol() === 'mail') ? $this->newline : '';
-		$body = '';
-
-		switch ($this->getContentType())
+		if (! $success)
 		{
-			case 'plain':
-
-				$hdr .= 'Content-Type: text/plain; charset=' . $this->charset . $this->newline
-						. 'Content-Transfer-Encoding: ' . $this->getEncoding();
-
-				if ($this->getProtocol() === 'mail')
-				{
-					$this->headerStr .= $hdr;
-					$this->finalBody  = $this->body;
-				}
-				else
-				{
-					$this->finalBody = $hdr . $this->newline . $this->newline . $this->body;
-				}
-
-				return;
-
-			case 'html':
-
-				if ($this->sendMultipart === false)
-				{
-					$hdr .= 'Content-Type: text/html; charset=' . $this->charset . $this->newline
-							. 'Content-Transfer-Encoding: quoted-printable';
-				}
-				else
-				{
-					$boundary = uniqid('B_ALT_', true);
-					$hdr     .= 'Content-Type: multipart/alternative; boundary="' . $boundary . '"';
-
-					$body .= $this->getMimeMessage() . $this->newline . $this->newline
-							. '--' . $boundary . $this->newline
-							. 'Content-Type: text/plain; charset=' . $this->charset . $this->newline
-							. 'Content-Transfer-Encoding: ' . $this->getEncoding() . $this->newline . $this->newline
-							. $this->getAltMessage() . $this->newline . $this->newline
-							. '--' . $boundary . $this->newline
-							. 'Content-Type: text/html; charset=' . $this->charset . $this->newline
-							. 'Content-Transfer-Encoding: quoted-printable' . $this->newline . $this->newline;
-				}
-
-				$this->finalBody = $body . $this->prepQuotedPrintable($this->body) . $this->newline . $this->newline;
-
-				if ($this->getProtocol() === 'mail')
-				{
-					$this->headerStr .= $hdr;
-				}
-				else
-				{
-					$this->finalBody = $hdr . $this->newline . $this->newline . $this->finalBody;
-				}
-
-				if ($this->sendMultipart !== false)
-				{
-					$this->finalBody .= '--' . $boundary . '--';
-				}
-
-				return;
-
-			case 'plain-attach':
-
-				$boundary = uniqid('B_ATC_', true);
-				$hdr     .= 'Content-Type: multipart/mixed; boundary="' . $boundary . '"';
-
-				if ($this->getProtocol() === 'mail')
-				{
-					$this->headerStr .= $hdr;
-				}
-
-				$body .= $this->getMimeMessage() . $this->newline
-						. $this->newline
-						. '--' . $boundary . $this->newline
-						. 'Content-Type: text/plain; charset=' . $this->charset . $this->newline
-						. 'Content-Transfer-Encoding: ' . $this->getEncoding() . $this->newline
-						. $this->newline
-						. $this->body . $this->newline . $this->newline;
-
-				$this->appendAttachments($body, $boundary);
-
-				break;
-			case 'html-attach':
-
-				$alt_boundary  = uniqid('B_ALT_', true);
-				$last_boundary = null;
-
-				if ($this->attachmentsHaveMultipart('mixed'))
-				{
-					$atc_boundary  = uniqid('B_ATC_', true);
-					$hdr          .= 'Content-Type: multipart/mixed; boundary="' . $atc_boundary . '"';
-					$last_boundary = $atc_boundary;
-				}
-
-				if ($this->attachmentsHaveMultipart('related'))
-				{
-					$rel_boundary        = uniqid('B_REL_', true);
-					$rel_boundary_header = 'Content-Type: multipart/related; boundary="' . $rel_boundary . '"';
-
-					if (isset($last_boundary))
-					{
-						$body .= '--' . $last_boundary . $this->newline . $rel_boundary_header;
-					}
-					else
-					{
-						$hdr .= $rel_boundary_header;
-					}
-
-					$last_boundary = $rel_boundary;
-				}
-
-				if ($this->getProtocol() === 'mail')
-				{
-					$this->headerStr .= $hdr;
-				}
-
-				static::strlen($body) && $body .= $this->newline . $this->newline;
-				$body                          .= $this->getMimeMessage() . $this->newline . $this->newline
-						. '--' . $last_boundary . $this->newline
-						. 'Content-Type: multipart/alternative; boundary="' . $alt_boundary . '"' . $this->newline . $this->newline
-						. '--' . $alt_boundary . $this->newline
-						. 'Content-Type: text/plain; charset=' . $this->charset . $this->newline
-						. 'Content-Transfer-Encoding: ' . $this->getEncoding() . $this->newline . $this->newline
-						. $this->getAltMessage() . $this->newline . $this->newline
-						. '--' . $alt_boundary . $this->newline
-						. 'Content-Type: text/html; charset=' . $this->charset . $this->newline
-						. 'Content-Transfer-Encoding: quoted-printable' . $this->newline . $this->newline
-						. $this->prepQuotedPrintable($this->body) . $this->newline . $this->newline
-						. '--' . $alt_boundary . '--' . $this->newline . $this->newline;
-
-				if (! empty($rel_boundary))
-				{
-					$body .= $this->newline . $this->newline;
-					$this->appendAttachments($body, $rel_boundary, 'related');
-				}
-
-				// multipart/mixed attachments
-				if (! empty($atc_boundary))
-				{
-					$body .= $this->newline . $this->newline;
-					$this->appendAttachments($body, $atc_boundary, 'mixed');
-				}
-
-				break;
+			throw MailerException::forSendFailure($protocol === 'mail' ? 'PHPMail' : ucfirst($protocol));
 		}
 
-		$this->finalBody = ($this->getProtocol() === 'mail') ? $body : $hdr . $this->newline . $this->newline . $body;
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Prepares attachment string
-	 *
-	 * @param string      &$body     Message body to append to
-	 * @param string      $boundary  Multipart boundary
-	 * @param string|null $multipart When provided, only attachments of this type will be processed
-	 *
-	 * @return string
-	 */
-	protected function appendAttachments(&$body, $boundary, $multipart = null)
-	{
-		for ($i = 0, $c = count($this->attachments); $i < $c; $i ++)
-		{
-			if (isset($multipart) && $this->attachments[$i]['multipart'] !== $multipart)
-			{
-				continue;
-			}
-
-			$name = isset($this->attachments[$i]['name'][1]) ? $this->attachments[$i]['name'][1] : basename($this->attachments[$i]['name'][0]);
-
-			$body .= '--' . $boundary . $this->newline
-					. 'Content-Type: ' . $this->attachments[$i]['type'] . '; name="' . $name . '"' . $this->newline
-					. 'Content-Disposition: ' . $this->attachments[$i]['disposition'] . ';' . $this->newline
-					. 'Content-Transfer-Encoding: base64' . $this->newline
-					. (empty($this->attachments[$i]['cid']) ? '' : 'Content-ID: <' . $this->attachments[$i]['cid'] . '>' . $this->newline)
-					. $this->newline
-					. $this->attachments[$i]['content'] . $this->newline;
-		}
+		$this->setErrorMessage(lang('Mailer.sent', [$protocol]));
 
-		// $name won't be set if no attachments were appended,
-		// and therefore a boundary wouldn't be necessary
-		empty($name) || $body .= '--' . $boundary . '--';
+		return true;
 	}
 
 	//--------------------------------------------------------------------
 
 	/**
-	 * Prep Quoted Printable
-	 *
-	 * Prepares string for Quoted-Printable Content-Transfer-Encoding
-	 * Refer to RFC 2045 http://www.ietf.org/rfc/rfc2045.txt
-	 *
-	 * @param string $str
+	 * Send using mail()
 	 *
-	 * @return string
+	 * @return boolean
 	 */
-	protected function prepQuotedPrintable($str)
+	protected function sendWithMail()
 	{
-		// ASCII code numbers for "safe" characters that can always be
-		// used literally, without encoding, as described in RFC 2049.
-		// http://www.ietf.org/rfc/rfc2049.txt
-		static $ascii_safe_chars = [
-			// ' (  )   +   ,   -   .   /   :   =   ?
-			39,
-			40,
-			41,
-			43,
-			44,
-			45,
-			46,
-			47,
-			58,
-			61,
-			63,
-			// numbers
-			48,
-			49,
-			50,
-			51,
-			52,
-			53,
-			54,
-			55,
-			56,
-			57,
-			// upper-case letters
-			65,
-			66,
-			67,
-			68,
-			69,
-			70,
-			71,
-			72,
-			73,
-			74,
-			75,
-			76,
-			77,
-			78,
-			79,
-			80,
-			81,
-			82,
-			83,
-			84,
-			85,
-			86,
-			87,
-			88,
-			89,
-			90,
-			// lower-case letters
-			97,
-			98,
-			99,
-			100,
-			101,
-			102,
-			103,
-			104,
-			105,
-			106,
-			107,
-			108,
-			109,
-			110,
-			111,
-			112,
-			113,
-			114,
-			115,
-			116,
-			117,
-			118,
-			119,
-			120,
-			121,
-			122,
-		];
-
-		// We are intentionally wrapping so mail servers will encode characters
-		// properly and MUAs will behave, so {unwrap} must go!
-		$str = str_replace(['{unwrap}', '{/unwrap}'], '', $str);
-
-		// RFC 2045 specifies CRLF as "\r\n".
-		// However, many developers choose to override that and violate
-		// the RFC rules due to (apparently) a bug in MS Exchange,
-		// which only works with "\n".
-		if ($this->CRLF === "\r\n")
+		if (is_array($this->recipients))
 		{
-			return quoted_printable_encode($str);
+			$this->recipients = implode(', ', $this->recipients);
 		}
 
-		// Reduce multiple spaces & remove nulls
-		$str = preg_replace(['| +|', '/\x00+/'], [' ', ''], $str);
+		// _validate_email_for_shell() below accepts by reference,
+		// so this needs to be assigned to a variable
+		$from = $this->cleanEmail($this->headers['Return-Path']);
 
-		// Standardize newlines
-		if (strpos($str, "\r") !== false)
+		if (! $this->validateEmailForShell($from))
 		{
-			$str = str_replace(["\r\n", "\r"], "\n", $str);
-		}
-
-		$escape = '=';
-		$output = '';
-
-		foreach (explode("\n", $str) as $line)
-		{
-			$length = static::strlen($line);
-			$temp   = '';
-
-			// Loop through each character in the line to add soft-wrap
-			// characters at the end of a line " =\r\n" and add the newly
-			// processed line(s) to the output (see comment on $crlf class property)
-			for ($i = 0; $i < $length; $i ++)
-			{
-				// Grab the next character
-				$char  = $line[$i];
-				$ascii = ord($char);
-
-				// Convert spaces and tabs but only if it's the end of the line
-				if ($ascii === 32 || $ascii === 9)
-				{
-					if ($i === ($length - 1))
-					{
-						$char = $escape . sprintf('%02s', dechex($ascii));
-					}
-				}
-				// DO NOT move this below the $ascii_safe_chars line!
-				//
-				// = (equals) signs are allowed by RFC2049, but must be encoded
-				// as they are the encoding delimiter!
-				elseif ($ascii === 61)
-				{
-					$char = $escape . strtoupper(sprintf('%02s', dechex($ascii)));  // =3D
-				}
-				elseif (! in_array($ascii, $ascii_safe_chars, true))
-				{
-					$char = $escape . strtoupper(sprintf('%02s', dechex($ascii)));
-				}
-
-				// If we're at the character limit, add the line to the output,
-				// reset our temp variable, and keep on chuggin'
-				if ((static::strlen($temp) + static::strlen($char)) >= 76)
-				{
-					$output .= $temp . $escape . $this->CRLF;
-					$temp    = '';
-				}
-
-				// Add the character to our temporary line
-				$temp .= $char;
-			}
-
-			// Add our completed line to the output
-			$output .= $temp . $this->CRLF;
-		}
-
-		// get rid of extra CRLF tacked onto the end
-		return static::substr($output, 0, static::strlen($this->CRLF) * -1);
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Prep Q Encoding
-	 *
-	 * Performs "Q Encoding" on a string for use in email headers.
-	 * It's related but not identical to quoted-printable, so it has its
-	 * own method.
-	 *
-	 * @param string $str
-	 *
-	 * @return string
-	 */
-	protected function prepQEncoding($str)
-	{
-		$str = str_replace(["\r", "\n"], '', $str);
-
-		if ($this->charset === 'UTF-8')
-		{
-			// Note: We used to have mb_encode_mimeheader() as the first choice
-			//       here, but it turned out to be buggy and unreliable. DO NOT
-			//       re-add it! -- Narf
-			if (extension_loaded('iconv'))
-			{
-				$output = @iconv_mime_encode(
-								'', $str, [
-									'scheme'           => 'Q',
-									'line-length'      => 76,
-									'input-charset'    => $this->charset,
-									'output-charset'   => $this->charset,
-									'line-break-chars' => $this->CRLF,
-								]);
-
-				// There are reports that iconv_mime_encode() might fail and return FALSE
-				if ($output !== false)
-				{
-					// iconv_mime_encode() will always put a header field name.
-					// We've passed it an empty one, but it still prepends our
-					// encoded string with ': ', so we need to strip it.
-					return static::substr($output, 2);
-				}
-
-				$chars = iconv_strlen($str, 'UTF-8');
-			}
-			elseif (extension_loaded('mbstring'))
-			{
-				$chars = mb_strlen($str, 'UTF-8');
-			}
-		}
-
-		// We might already have this set for UTF-8
-		isset($chars) || $chars = static::strlen($str);
-
-		$output = '=?' . $this->charset . '?Q?';
-		for ($i = 0, $length = static::strlen($output); $i < $chars; $i ++)
-		{
-			$chr = ($this->charset === 'UTF-8' && ICONV_ENABLED === true) ? '=' . implode('=', str_split(strtoupper(bin2hex(iconv_substr($str, $i, 1, $this->charset))), 2)) : '=' . strtoupper(bin2hex($str[$i]));
-
-			// RFC 2045 sets a limit of 76 characters per line.
-			// We'll append ?= to the end of each line though.
-			if ($length + ($l = static::strlen($chr)) > 74)
-			{
-				$output .= '?=' . $this->CRLF // EOL
-						. ' =?' . $this->charset . '?Q?' . $chr; // New line
-				$length  = 6 + static::strlen($this->charset) + $l; // Reset the length for the new line
-			}
-			else
-			{
-				$output .= $chr;
-				$length += $l;
-			}
-		}
-
-		// End the header
-		return $output . '?=';
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Send an Email
-	 *
-	 * @param Email $email
-	 *
-	 * @return boolean
-	 */
-	public function send(Email $email)
-	{
-		if (! isset($this->headers['From']) && ! empty($this->fromEmail))
-		{
-			$this->setFrom($this->fromEmail, $this->fromName);
-		}
-
-		if (! isset($this->headers['From']))
-		{
-				throw MailerException::forNoFrom();
-		}
-
-		if ($this->replyToFlag === false)
-		{
-			$this->setReplyTo($this->headers['From']);
-		}
-
-		if (empty($this->recipients) && ! isset($this->headers['To']) && empty($this->BCCArray) && ! isset($this->headers['Bcc']) && ! isset($this->headers['Cc'])
-		)
-		{
-				throw MailerException::forNoRecipients();
-		}
-
-		$this->buildHeaders();
-
-		if ($this->BCCBatchMode && count($this->BCCArray) > $this->BCCBatchSize)
-		{
-			$this->batchBCCSend();
-
-			if ($autoClear)
-			{
-				$this->clear();
-			}
-
-			return true;
-		}
-
-		$this->buildMessage();
-		$result = $this->spoolEmail();
-
-		if ($result && $autoClear)
-		{
-			$this->clear();
-		}
-
-		return $result;
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Batch Bcc Send. Sends groups of BCCs in batches
-	 */
-	public function batchBCCSend()
-	{
-		$float = $this->BCCBatchSize - 1;
-		$set   = '';
-		$chunk = [];
-
-		for ($i = 0, $c = count($this->BCCArray); $i < $c; $i ++)
-		{
-			if (isset($this->BCCArray[$i]))
-			{
-				$set .= ', ' . $this->BCCArray[$i];
-			}
-
-			if ($i === $float)
-			{
-				$chunk[] = static::substr($set, 1);
-				$float  += $this->BCCBatchSize;
-				$set     = '';
-			}
-
-			if ($i === $c - 1)
-			{
-				$chunk[] = static::substr($set, 1);
-			}
-		}
-
-		for ($i = 0, $c = count($chunk); $i < $c; $i ++)
-		{
-			unset($this->headers['Bcc']);
-
-			$bcc = $this->cleanEmail($this->stringToArray($chunk[$i]));
-
-			if ($this->protocol !== 'smtp')
-			{
-				$this->setHeader('Bcc', implode(', ', $bcc));
-			}
-			else
-			{
-				$this->BCCArray = $bcc;
-			}
-
-			$this->buildMessage();
-			$this->spoolEmail();
-		}
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Unwrap special elements
-	 */
-	protected function unwrapSpecials()
-	{
-		$this->finalBody = preg_replace_callback(
-				'/\{unwrap\}(.*?)\{\/unwrap\}/si', [
-					$this,
-					'removeNLCallback',
-				], $this->finalBody
-		);
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Strip line-breaks via callback
-	 *
-	 * @param string $matches
-	 *
-	 * @return string
-	 */
-	protected function removeNLCallback($matches)
-	{
-		if (strpos($matches[1], "\r") !== false || strpos($matches[1], "\n") !== false)
-		{
-			$matches[1] = str_replace(["\r\n", "\r", "\n"], '', $matches[1]);
-		}
-
-		return $matches[1];
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Spool mail to the mail server
-	 *
-	 * @return boolean
-	 */
-	protected function spoolEmail()
-	{
-		$this->unwrapSpecials();
-
-		$protocol = $this->getProtocol();
-		$method   = 'sendWith' . ucfirst($protocol);
-		try
-		{
-			$success = $this->$method();
-		}
-		catch (\ErrorException $e)
-		{
-			$success = false;
-			$this->logger->error('Mailer: ' . $method . ' throwed ' . $e->getMessage());
-		}
-
-		if (! $success)
-		{
-				throw MailerException::forSendFailure($protocol === 'mail' ? 'PHPMail' : ucfirst($protocol));
-		}
-
-		$this->setErrorMessage(lang('Mailer.sent', [$protocol]));
-
-		return true;
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Validate email for shell
-	 *
-	 * Applies stricter, shell-safe validation to email addresses.
-	 * Introduced to prevent RCE via sendmail's -f option.
-	 *
-	 * @see     https://github.com/codeigniter4/CodeIgniter/issues/4963
-	 * @see     https://gist.github.com/Zenexer/40d02da5e07f151adeaeeaa11af9ab36
-	 * @license https://creativecommons.org/publicdomain/zero/1.0/    CC0 1.0, Public Domain
-	 *
-	 * Credits for the base concept go to Paul Buonopane <paul@namepros.com>
-	 *
-	 * @param string &$email
-	 *
-	 * @return boolean
-	 */
-	protected function validateEmailForShell(&$email)
-	{
-		if (function_exists('idn_to_ascii') && $atpos = strpos($email, '@'))
-		{
-			$email = static::substr($email, 0, ++ $atpos) . idn_to_ascii(
-							static::substr($email, $atpos), 0, INTL_IDNA_VARIANT_UTS46
-			);
-		}
-
-		return (filter_var($email, FILTER_VALIDATE_EMAIL) === $email && preg_match('#\A[a-z0-9._+-]+@[a-z0-9.-]{1,253}\z#i', $email));
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Send using mail()
-	 *
-	 * @return boolean
-	 */
-	protected function sendWithMail()
-	{
-		if (is_array($this->recipients))
-		{
-			$this->recipients = implode(', ', $this->recipients);
-		}
-
-		// _validate_email_for_shell() below accepts by reference,
-		// so this needs to be assigned to a variable
-		$from = $this->cleanEmail($this->headers['Return-Path']);
-
-		if (! $this->validateEmailForShell($from))
-		{
-			return mail($this->recipients, $this->subject, $this->finalBody, $this->headerStr);
+			return mail($this->recipients, $this->subject, $this->finalBody, $this->headerStr);
 		}
 
 		// most documentation of sendmail using the "-f" flag lacks a space after it, however
 		// we've encountered servers that seem to require it to be in place.
 		return mail($this->recipients, $this->subject, $this->finalBody, $this->headerStr, '-f ' . $from);
 	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Send using Sendmail
-	 *
-	 * @return boolean
-	 */
-	protected function sendWithSendmail()
-	{
-		// _validate_email_for_shell() below accepts by reference,
-		// so this needs to be assigned to a variable
-		$from = $this->cleanEmail($this->headers['From']);
-		if ($this->validateEmailForShell($from))
-		{
-			$from = '-f ' . $from;
-		}
-		else
-		{
-			$from = '';
-		}
-
-		// is popen() enabled?
-		if (! function_usable('popen') || false === ($fp = @popen($this->mailPath . ' -oi ' . $from . ' -t', 'w')))
-		{
-			// server probably has popen disabled, so nothing we can do to get a verbose error.
-			return false;
-		}
-
-		fputs($fp, $this->headerStr);
-		fputs($fp, $this->finalBody);
-
-		$status = pclose($fp);
-
-		if ($status !== 0)
-		{
-				throw MailerException::forNosocket($status);
-		}
-
-		return true;
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Send using SMTP
-	 *
-	 * @return boolean
-	 */
-	protected function sendWithSmtp()
-	{
-		if ($this->SMTPHost === '')
-		{
-				throw MailerException::forNoHostname();
-		}
-
-		if (! $this->SMTPConnect() || ! $this->SMTPAuthenticate())
-		{
-			return false;
-		}
-
-		if (! $this->sendCommand('from', $this->cleanEmail($this->headers['From'])))
-		{
-			$this->SMTPEnd();
-
-			return false;
-		}
-
-		foreach ($this->recipients as $val)
-		{
-			if (! $this->sendCommand('to', $val))
-			{
-				$this->SMTPEnd();
-
-				return false;
-			}
-		}
-
-		foreach ($this->CCArray as $val)
-		{
-			if ($val !== '' && ! $this->sendCommand('to', $val))
-			{
-				$this->SMTPEnd();
-
-				return false;
-			}
-		}
-
-		foreach ($this->BCCArray as $val)
-		{
-			if ($val !== '' && ! $this->sendCommand('to', $val))
-			{
-				$this->SMTPEnd();
-
-				return false;
-			}
-		}
-
-		if (! $this->sendCommand('data'))
-		{
-			$this->SMTPEnd();
-
-			return false;
-		}
-
-		// perform dot transformation on any lines that begin with a dot
-		$this->sendData($this->headerStr . preg_replace('/^\./m', '..$1', $this->finalBody));
-
-		$this->sendData('.');
-		$reply = $this->getSMTPData();
-		$this->setErrorMessage($reply);
-
-		$this->SMTPEnd();
-
-		if (strpos($reply, '250') !== 0)
-		{
-				throw MailerException::forSMTPError($reply);
-		}
-
-		return true;
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * SMTP End
-	 *
-	 * Shortcut to send RSET or QUIT depending on keep-alive
-	 */
-	protected function SMTPEnd()
-	{
-		$this->sendCommand($this->SMTPKeepAlive ? 'reset' : 'quit');
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * SMTP Connect
-	 *
-	 * @return string
-	 */
-	protected function SMTPConnect()
-	{
-		if (is_resource($this->SMTPConnect))
-		{
-			return true;
-		}
-
-		$ssl = ($this->SMTPCrypto === 'ssl') ? 'ssl://' : '';
-
-		$this->SMTPConnect = fsockopen(
-				$ssl . $this->SMTPHost, $this->SMTPPort, $errno, $errstr, $this->SMTPTimeout
-		);
-
-		if (! is_resource($this->SMTPConnect))
-		{
-				throw MailerException::forSMTPError($errno . ' ' . $errstr);
-		}
-
-		stream_set_timeout($this->SMTPConnect, $this->SMTPTimeout);
-		$this->setErrorMessage($this->getSMTPData());
-
-		if ($this->SMTPCrypto === 'tls')
-		{
-			$this->sendCommand('hello');
-			$this->sendCommand('starttls');
-
-			$crypto = stream_socket_enable_crypto($this->SMTPConnect, true, STREAM_CRYPTO_METHOD_TLS_CLIENT);
-
-			if ($crypto !== true)
-			{
-				throw MailerException::forSMTPError($this->getSMTPData());
-			}
-		}
-
-		return $this->sendCommand('hello');
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Send SMTP command
-	 *
-	 * @param string $cmd
-	 * @param string $data
-	 *
-	 * @return boolean
-	 */
-	protected function sendCommand($cmd, $data = '')
-	{
-		switch ($cmd)
-		{
-			case 'hello':
-				if ($this->SMTPAuth || $this->getEncoding() === '8bit')
-				{
-					$this->sendData('EHLO ' . $this->getHostname());
-				}
-				else
-				{
-					$this->sendData('HELO ' . $this->getHostname());
-				}
-
-				$resp = 250;
-				break;
-			case 'starttls':
-				$this->sendData('STARTTLS');
-				$resp = 220;
-				break;
-			case 'from':
-				$this->sendData('MAIL FROM:<' . $data . '>');
-				$resp = 250;
-				break;
-			case 'to':
-				if ($this->DSN)
-				{
-					$this->sendData('RCPT TO:<' . $data . '> NOTIFY=SUCCESS,DELAY,FAILURE ORCPT=rfc822;' . $data);
-				}
-				else
-				{
-					$this->sendData('RCPT TO:<' . $data . '>');
-				}
-				$resp = 250;
-				break;
-			case 'data':
-				$this->sendData('DATA');
-				$resp = 354;
-				break;
-			case 'reset':
-				$this->sendData('RSET');
-				$resp = 250;
-				break;
-			case 'quit':
-				$this->sendData('QUIT');
-				$resp = 221;
-				break;
-		}
-
-		$reply = $this->getSMTPData();
-
-		$this->debugMessage[] = '<pre>' . $cmd . ': ' . $reply . '</pre>';
-
-		if ((int) static::substr($reply, 0, 3) !== $resp)
-		{
-				throw MailerException::forSMTPError($reply);
-		}
-
-		if ($cmd === 'quit')
-		{
-			fclose($this->SMTPConnect);
-		}
-
-		return true;
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * SMTP Authenticate
-	 *
-	 * @return boolean
-	 */
-	protected function SMTPAuthenticate()
-	{
-		if (! $this->SMTPAuth)
-		{
-			return true;
-		}
-
-		if ($this->SMTPUser === '' && $this->SMTPPass === '')
-		{
-				throw MailerException::forNoSMTPAuth();
-		}
-
-		$this->sendData('AUTH LOGIN');
-		$reply = $this->getSMTPData();
-
-		if (strpos($reply, '503') === 0)    // Already authenticated
-		{
-			return true;
-		}
-		elseif (strpos($reply, '334') !== 0)
-		{
-				throw MailerException::forFailedSMTPLogin($reply);
-		}
-
-		$this->sendData(base64_encode($this->SMTPUser));
-		$reply = $this->getSMTPData();
-
-		if (strpos($reply, '334') !== 0)
-		{
-				throw MailerException::forSMTPAuthUsername($reply);
-		}
-
-		$this->sendData(base64_encode($this->SMTPPass));
-		$reply = $this->getSMTPData();
-
-		if (strpos($reply, '235') !== 0)
-		{
-				throw MailerException::forSMTPAuthPassword($reply);
-		}
-
-		if ($this->SMTPKeepAlive)
-		{
-			$this->SMTPAuth = false;
-		}
-
-		return true;
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Send SMTP data
-	 *
-	 * @param string $data
-	 *
-	 * @return boolean
-	 */
-	protected function sendData($data)
-	{
-		$data .= $this->newline;
-		for ($written = $timestamp = 0, $length = static::strlen($data); $written < $length; $written += $result)
-		{
-			if (($result = fwrite($this->SMTPConnect, static::substr($data, $written))) === false)
-			{
-				break;
-			}
-			// See https://bugs.php.net/bug.php?id=39598 and http://php.net/manual/en/function.fwrite.php#96951
-			elseif ($result === 0)
-			{
-				if ($timestamp === 0)
-				{
-					$timestamp = time();
-				}
-				elseif ($timestamp < (time() - $this->SMTPTimeout))
-				{
-					$result = false;
-					break;
-				}
-
-				usleep(250000);
-				continue;
-			}
-			else
-			{
-				$timestamp = 0;
-			}
-		}
-
-		if ($result === false)
-		{
-				throw MailerException::forSMTPDataFailure($data);
-		}
-
-		return true;
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Get SMTP data
-	 *
-	 * @return string
-	 */
-	protected function getSMTPData()
-	{
-		$data = '';
-
-		while ($str = fgets($this->SMTPConnect, 512))
-		{
-			$data .= $str;
-
-			if ($str[3] === ' ')
-			{
-				break;
-			}
-		}
-
-		return $data;
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Get Hostname
-	 *
-	 * There are only two legal types of hostname - either a fully
-	 * qualified domain name (eg: "mail.example.com") or an IP literal
-	 * (eg: "[1.2.3.4]").
-	 *
-	 * @link https://tools.ietf.org/html/rfc5321#section-2.3.5
-	 * @link http://cbl.abuseat.org/namingproblems.html
-	 *
-	 * @return string
-	 */
-	protected function getHostname()
-	{
-		if (isset($_SERVER['SERVER_NAME']))
-		{
-			return $_SERVER['SERVER_NAME'];
-		}
-
-		return isset($_SERVER['SERVER_ADDR']) ? '[' . $_SERVER['SERVER_ADDR'] . ']' : '[127.0.0.1]';
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Get Debug Message
-	 *
-	 * @param array $include List of raw data chunks to include in the output
-	 *                       Valid options are: 'headers', 'subject', 'body'
-	 *
-	 * @return string
-	 */
-	public function printDebugger($include = ['headers', 'subject', 'body'])
-	{
-		$msg = implode('', $this->debugMessage);
-
-		// Determine which parts of our raw data needs to be printed
-		$raw_data                      = '';
-		is_array($include) || $include = [$include];
-
-		in_array('headers', $include, true) && $raw_data  = htmlspecialchars($this->headerStr) . "\n";
-		in_array('subject', $include, true) && $raw_data .= htmlspecialchars($this->subject) . "\n";
-		in_array('body', $include, true) && $raw_data    .= htmlspecialchars($this->finalBody);
-
-		return $msg . ($raw_data === '' ? '' : '<pre>' . $raw_data . '</pre>');
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Set Message
-	 *
-	 * @param string $msg
-	 */
-	protected function setErrorMessage($msg)
-	{
-		$this->debugMessage[] = $msg . '<br />';
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Mime Types
-	 *
-	 * @param string $ext
-	 *
-	 * @return string
-	 */
-	protected function mimeTypes($ext = '')
-	{
-		$mime = Mimes::guessTypeFromExtension(strtolower($ext));
-
-		return ! empty($mime) ? $mime : 'application/x-unknown-content-type';
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Destructor
-	 */
-	public function __destruct()
-	{
-		is_resource($this->SMTPConnect) && $this->sendCommand('quit');
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Byte-safe strlen()
-	 *
-	 * @param string $str
-	 *
-	 * @return integer
-	 */
-	protected static function strlen($str)
-	{
-		return (static::$func_overload) ? mb_strlen($str, '8bit') : strlen($str);
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Byte-safe substr()
-	 *
-	 * @param string       $str
-	 * @param integer      $start
-	 * @param integer|null $length
-	 *
-	 * @return string
-	 */
-	protected static function substr($str, $start, $length = null)
-	{
-		if (static::$func_overload)
-		{
-			return mb_substr($str, $start, $length, '8bit');
-		}
-
-		return isset($length) ? substr($str, $start, $length) : substr($str, $start);
-	}
-
 }
diff --git a/system/Mailer/Handlers/SendmailHandler.php b/system/Mailer/Handlers/SendmailHandler.php
index 5e339579622e..35d24cf07d14 100644
--- a/system/Mailer/Handlers/SendmailHandler.php
+++ b/system/Mailer/Handlers/SendmailHandler.php
@@ -1,1140 +1,46 @@
 <?php
-namespace CodeIgniter\Mailer\Handlers;
 
 /**
- * CodeIgniter
- *
- * An open source application development framework for PHP
- *
- * This content is released under the MIT License (MIT)
- *
- * Copyright (c) 2014 - 2018, British Columbia Institute of Technology
+ * This file is part of the CodeIgniter 4 framework.
  *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
+ * (c) CodeIgniter Foundation <admin@codeigniter.com>
  *
- * The above copyright notice and this permission notice shall be included in
- * all copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
- * THE SOFTWARE.
- *
- * @package    CodeIgniter
- * @author     EllisLab Dev Team
- * @copyright  Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright  Copyright (c) 2014 - 2018, British Columbia Institute of Technology (http://bcit.ca/)
- * @license    http://opensource.org/licenses/MIT    MIT License
- * @link       https://codeigniter.com
- * @since      Version 1.0.0
- * @filesource
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
  */
 
+namespace CodeIgniter\Mailer\Handlers;
+
 use CodeIgniter\Mailer\Email;
 use CodeIgniter\Mailer\Exceptions\MailerException;
-use Config\Mimes;
-use Psr\Log\LoggerAwareTrait;
 
-/**
- * CodeIgniter Mailer Class
- *
- * Permits email to be sent using Mail, Sendmail, or SMTP.
- *
- * @package    CodeIgniter
- * @subpackage Libraries
- * @category   Libraries
- * @author     EllisLab Dev Team
- * @link       https://codeigniter.com/user_guide/libraries/email.html
- */
 class SendmailHandler extends BaseHandler
 {
-
-	/**
-	 * Message format.
-	 *
-	 * @var string 'text' or 'html'
-	 */
-	public $mailType = 'text';
-
-	/**
-	 * Character set (default: utf-8)
-	 *
-	 * @var string
-	 */
-	public $charset = 'utf-8';
-
-	/**
-	 * Alternative message (for HTML messages only)
-	 *
-	 * @var string
-	 */
-	public $altMessage = '';
-
-	/**
-	 * Whether to validate e-mail addresses.
-	 *
-	 * @var boolean
-	 */
-	public $validate = true;
-
-	/**
-	 * X-Priority header value.
-	 *
-	 * @var integer 1-5
-	 */
-	public $priority = 3;            // Default priority (1 - 5)
-
-	/**
-	 * Newline character sequence.
-	 * Use "\r\n" to comply with RFC 822.
-	 *
-	 * @link http://www.ietf.org/rfc/rfc822.txt
-	 * @var  string "\r\n" or "\n"
-	 */
-	public $newline = "\n";            // Default newline. "\r\n" or "\n" (Use "\r\n" to comply with RFC 822)
-
-	/**
-	 * CRLF character sequence
-	 *
-	 * RFC 2045 specifies that for 'quoted-printable' encoding,
-	 * "\r\n" must be used. However, it appears that some servers
-	 * (even on the receiving end) don't handle it properly and
-	 * switching to "\n", while improper, is the only solution
-	 * that seems to work for all environments.
-	 *
-	 * @link http://www.ietf.org/rfc/rfc822.txt
-	 * @var  string
-	 */
-	public $CRLF = "\n";
-
-	/**
-	 * Whether to use Delivery Status Notification.
-	 *
-	 * @var boolean
-	 */
-	public $DSN = false;
-
-	/**
-	 * Whether to send multipart alternatives.
-	 * Yahoo! doesn't seem to like these.
-	 *
-	 * @var boolean
-	 */
-	public $sendMultipart = true;
-
-	/**
-	 * Whether to send messages to BCC recipients in batches.
-	 *
-	 * @var boolean
-	 */
-	public $BCCBatchMode = false;
-
-	/**
-	 * BCC Batch max number size.
-	 *
-	 * @see self::$BCCBatchMode
-	 * @var integer
-	 */
-	public $BCCBatchSize = 200;
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Subject header
-	 *
-	 * @var string
-	 */
-	protected $subject = '';
-
-	/**
-	 * Message body
-	 *
-	 * @var string
-	 */
-	protected $body = '';
-
-	/**
-	 * Final message body to be sent.
-	 *
-	 * @var string
-	 */
-	protected $finalBody = '';
-
-	/**
-	 * Final headers to send
-	 *
-	 * @var string
-	 */
-	protected $headerStr = '';
-
-	/**
-	 * SMTP Connection socket placeholder
-	 *
-	 * @var resource
-	 */
-	protected $SMTPConnect = '';
-
-	/**
-	 * Mail encoding
-	 *
-	 * @var string '8bit' or '7bit'
-	 */
-	protected $encoding = '8bit';
-
-	/**
-	 * Whether to send a Reply-To header
-	 *
-	 * @var boolean
-	 */
-	protected $replyToFlag = false;
-
-	/**
-	 * Debug messages
-	 *
-	 * @see self::printDebugger()
-	 * @var array
-	 */
-	protected $debugMessage = [];
-
-	/**
-	 * Recipients
-	 *
-	 * @var array
-	 */
-	protected $recipients = [];
-
-	/**
-	 * CC Recipients
-	 *
-	 * @var array
-	 */
-	protected $CCArray = [];
-
-	/**
-	 * BCC Recipients
-	 *
-	 * @var array
-	 */
-	protected $BCCArray = [];
-
-	/**
-	 * Message headers
-	 *
-	 * @var array
-	 */
-	protected $headers = [];
-
-	/**
-	 * Attachment data
-	 *
-	 * @var array
-	 */
-	protected $attachments = [];
-
-	/**
-	 * Valid $protocol values
-	 *
-	 * @see self::$protocol
-	 * @var array
-	 */
-	protected $protocols = [
-		'mail',
-		'sendmail',
-		'smtp',
-	];
-
-	/**
-	 * Base charsets
-	 *
-	 * Character sets valid for 7-bit encoding,
-	 * excluding language suffix.
-	 *
-	 * @var array
-	 */
-	protected $baseCharsets = [
-		'us-ascii',
-		'iso-2022-',
-	];
-
-	/**
-	 * Bit depths
-	 *
-	 * Valid mail encodings
-	 *
-	 * @see self::$encoding
-	 * @var array
-	 */
-	protected $bitDepths = [
-		'7bit',
-		'8bit',
-	];
-
-	/**
-	 * $priority translations
-	 *
-	 * Actual values to send with the X-Priority header
-	 *
-	 * @var array
-	 */
-	protected $priorities = [
-		1 => '1 (Highest)',
-		2 => '2 (High)',
-		3 => '3 (Normal)',
-		4 => '4 (Low)',
-		5 => '5 (Lowest)',
-	];
-
-	/**
-	 * mbstring.func_overload flag
-	 *
-	 * @var boolean
-	 */
-	protected static $func_overload;
-
-	/**
-	 * Logger instance to record error messages and awarnings.
-	 *
-	 * @var \PSR\Log\LoggerInterface
-	 */
-	protected $logger;
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Constructor - Sets Preferences
-	 *
-	 * The constructor can be passed an array of config values
-	 *
-	 * @param array|null $config
-	 */
-	public function __construct($config = null)
-	{
-		$this->protocol = 'sendmail';
-		$this->initialize($config);
-
-		log_message('info', 'Mailer Class Initialized');
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Initialize preferences
-	 *
-	 * @param array|\Config\Mailer $config
-	 *
-	 * @return $this
-	 */
-	public function initialize($config)
-	{
-		$this->clear();
-
-		if ($config instanceof \Config\Mailer)
-		{
-			$config = get_object_vars($config);
-		}
-
-		foreach (get_class_vars(get_class($this)) as $key => $value)
-		{
-			if (property_exists($this, $key) && isset($config[$key]))
-			{
-				$method = 'set' . ucfirst($key);
-
-				if (method_exists($this, $method))
-				{
-					$this->$method($config[$key]);
-				}
-				else
-				{
-					$this->$key = $config[$key];
-				}
-			}
-		}
-
-		$this->charset  = strtoupper($this->charset);
-		$this->SMTPAuth = isset($this->SMTPUser[0], $this->SMTPPass[0]);
-
-		return $this;
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Initialize the Data
-	 *
-	 * @param boolean $clearAttachments
-	 *
-	 * @return $this
-	 */
-	public function clear($clearAttachments = false)
-	{
-		$this->subject      = '';
-		$this->body         = '';
-		$this->finalBody    = '';
-		$this->headerStr    = '';
-		$this->replyToFlag  = false;
-		$this->recipients   = [];
-		$this->CCArray      = [];
-		$this->BCCArray     = [];
-		$this->headers      = [];
-		$this->debugMessage = [];
-
-		//      $this->setHeader('Date', $this->setDate());
-
-		if ($clearAttachments !== false)
-		{
-			$this->attachments = [];
-		}
-
-		return $this;
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Build final headers
-	 */
-	protected function buildHeaders()
-	{
-		$this->setHeader('User-Agent', $this->userAgent);
-		$this->setHeader('X-Sender', $this->cleanEmail($this->headers['From']));
-		$this->setHeader('X-Mailer', $this->userAgent);
-		$this->setHeader('X-Priority', $this->priorities[$this->priority]);
-		$this->setHeader('Message-ID', $this->getMessageID());
-		$this->setHeader('Mime-Version', '1.0');
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Write Headers as a string
-	 */
-	protected function writeHeaders()
-	{
-		if ($this->protocol === 'mail')
-		{
-			if (isset($this->headers['Subject']))
-			{
-				$this->subject = $this->headers['Subject'];
-				unset($this->headers['Subject']);
-			}
-		}
-
-		reset($this->headers);
-		$this->headerStr = '';
-
-		foreach ($this->headers as $key => $val)
-		{
-			$val = trim($val);
-
-			if ($val !== '')
-			{
-				$this->headerStr .= $key . ': ' . $val . $this->newline;
-			}
-		}
-
-		if ($this->getProtocol() === 'mail')
-		{
-			$this->headerStr = rtrim($this->headerStr);
-		}
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Build Final Body and attachments
-	 */
-	protected function buildMessage()
-	{
-		if ($this->wordWrap === true && $this->mailType !== 'html')
-		{
-			$this->body = $this->wordWrap($this->body);
-		}
-
-		$this->writeHeaders();
-
-		$hdr  = ($this->getProtocol() === 'mail') ? $this->newline : '';
-		$body = '';
-
-		switch ($this->getContentType())
-		{
-			case 'plain':
-
-				$hdr .= 'Content-Type: text/plain; charset=' . $this->charset . $this->newline
-						. 'Content-Transfer-Encoding: ' . $this->getEncoding();
-
-				if ($this->getProtocol() === 'mail')
-				{
-					$this->headerStr .= $hdr;
-					$this->finalBody  = $this->body;
-				}
-				else
-				{
-					$this->finalBody = $hdr . $this->newline . $this->newline . $this->body;
-				}
-
-				return;
-
-			case 'html':
-
-				if ($this->sendMultipart === false)
-				{
-					$hdr .= 'Content-Type: text/html; charset=' . $this->charset . $this->newline
-							. 'Content-Transfer-Encoding: quoted-printable';
-				}
-				else
-				{
-					$boundary = uniqid('B_ALT_', true);
-					$hdr     .= 'Content-Type: multipart/alternative; boundary="' . $boundary . '"';
-
-					$body .= $this->getMimeMessage() . $this->newline . $this->newline
-							. '--' . $boundary . $this->newline
-							. 'Content-Type: text/plain; charset=' . $this->charset . $this->newline
-							. 'Content-Transfer-Encoding: ' . $this->getEncoding() . $this->newline . $this->newline
-							. $this->getAltMessage() . $this->newline . $this->newline
-							. '--' . $boundary . $this->newline
-							. 'Content-Type: text/html; charset=' . $this->charset . $this->newline
-							. 'Content-Transfer-Encoding: quoted-printable' . $this->newline . $this->newline;
-				}
-
-				$this->finalBody = $body . $this->prepQuotedPrintable($this->body) . $this->newline . $this->newline;
-
-				if ($this->getProtocol() === 'mail')
-				{
-					$this->headerStr .= $hdr;
-				}
-				else
-				{
-					$this->finalBody = $hdr . $this->newline . $this->newline . $this->finalBody;
-				}
-
-				if ($this->sendMultipart !== false)
-				{
-					$this->finalBody .= '--' . $boundary . '--';
-				}
-
-				return;
-
-			case 'plain-attach':
-
-				$boundary = uniqid('B_ATC_', true);
-				$hdr     .= 'Content-Type: multipart/mixed; boundary="' . $boundary . '"';
-
-				if ($this->getProtocol() === 'mail')
-				{
-					$this->headerStr .= $hdr;
-				}
-
-				$body .= $this->getMimeMessage() . $this->newline
-						. $this->newline
-						. '--' . $boundary . $this->newline
-						. 'Content-Type: text/plain; charset=' . $this->charset . $this->newline
-						. 'Content-Transfer-Encoding: ' . $this->getEncoding() . $this->newline
-						. $this->newline
-						. $this->body . $this->newline . $this->newline;
-
-				$this->appendAttachments($body, $boundary);
-
-				break;
-			case 'html-attach':
-
-				$alt_boundary  = uniqid('B_ALT_', true);
-				$last_boundary = null;
-
-				if ($this->attachmentsHaveMultipart('mixed'))
-				{
-					$atc_boundary  = uniqid('B_ATC_', true);
-					$hdr          .= 'Content-Type: multipart/mixed; boundary="' . $atc_boundary . '"';
-					$last_boundary = $atc_boundary;
-				}
-
-				if ($this->attachmentsHaveMultipart('related'))
-				{
-					$rel_boundary        = uniqid('B_REL_', true);
-					$rel_boundary_header = 'Content-Type: multipart/related; boundary="' . $rel_boundary . '"';
-
-					if (isset($last_boundary))
-					{
-						$body .= '--' . $last_boundary . $this->newline . $rel_boundary_header;
-					}
-					else
-					{
-						$hdr .= $rel_boundary_header;
-					}
-
-					$last_boundary = $rel_boundary;
-				}
-
-				if ($this->getProtocol() === 'mail')
-				{
-					$this->headerStr .= $hdr;
-				}
-
-				static::strlen($body) && $body .= $this->newline . $this->newline;
-				$body                          .= $this->getMimeMessage() . $this->newline . $this->newline
-						. '--' . $last_boundary . $this->newline
-						. 'Content-Type: multipart/alternative; boundary="' . $alt_boundary . '"' . $this->newline . $this->newline
-						. '--' . $alt_boundary . $this->newline
-						. 'Content-Type: text/plain; charset=' . $this->charset . $this->newline
-						. 'Content-Transfer-Encoding: ' . $this->getEncoding() . $this->newline . $this->newline
-						. $this->getAltMessage() . $this->newline . $this->newline
-						. '--' . $alt_boundary . $this->newline
-						. 'Content-Type: text/html; charset=' . $this->charset . $this->newline
-						. 'Content-Transfer-Encoding: quoted-printable' . $this->newline . $this->newline
-						. $this->prepQuotedPrintable($this->body) . $this->newline . $this->newline
-						. '--' . $alt_boundary . '--' . $this->newline . $this->newline;
-
-				if (! empty($rel_boundary))
-				{
-					$body .= $this->newline . $this->newline;
-					$this->appendAttachments($body, $rel_boundary, 'related');
-				}
-
-				// multipart/mixed attachments
-				if (! empty($atc_boundary))
-				{
-					$body .= $this->newline . $this->newline;
-					$this->appendAttachments($body, $atc_boundary, 'mixed');
-				}
-
-				break;
-		}
-
-		$this->finalBody = ($this->getProtocol() === 'mail') ? $body : $hdr . $this->newline . $this->newline . $body;
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Prepares attachment string
-	 *
-	 * @param string      &$body     Message body to append to
-	 * @param string      $boundary  Multipart boundary
-	 * @param string|null $multipart When provided, only attachments of this type will be processed
-	 *
-	 * @return string
-	 */
-	protected function appendAttachments(&$body, $boundary, $multipart = null)
-	{
-		for ($i = 0, $c = count($this->attachments); $i < $c; $i ++)
-		{
-			if (isset($multipart) && $this->attachments[$i]['multipart'] !== $multipart)
-			{
-				continue;
-			}
-
-			$name = isset($this->attachments[$i]['name'][1]) ? $this->attachments[$i]['name'][1] : basename($this->attachments[$i]['name'][0]);
-
-			$body .= '--' . $boundary . $this->newline
-					. 'Content-Type: ' . $this->attachments[$i]['type'] . '; name="' . $name . '"' . $this->newline
-					. 'Content-Disposition: ' . $this->attachments[$i]['disposition'] . ';' . $this->newline
-					. 'Content-Transfer-Encoding: base64' . $this->newline
-					. (empty($this->attachments[$i]['cid']) ? '' : 'Content-ID: <' . $this->attachments[$i]['cid'] . '>' . $this->newline)
-					. $this->newline
-					. $this->attachments[$i]['content'] . $this->newline;
-		}
-
-		// $name won't be set if no attachments were appended,
-		// and therefore a boundary wouldn't be necessary
-		empty($name) || $body .= '--' . $boundary . '--';
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Prep Quoted Printable
-	 *
-	 * Prepares string for Quoted-Printable Content-Transfer-Encoding
-	 * Refer to RFC 2045 http://www.ietf.org/rfc/rfc2045.txt
-	 *
-	 * @param string $str
-	 *
-	 * @return string
-	 */
-	protected function prepQuotedPrintable($str)
-	{
-		// ASCII code numbers for "safe" characters that can always be
-		// used literally, without encoding, as described in RFC 2049.
-		// http://www.ietf.org/rfc/rfc2049.txt
-		static $ascii_safe_chars = [
-			// ' (  )   +   ,   -   .   /   :   =   ?
-			39,
-			40,
-			41,
-			43,
-			44,
-			45,
-			46,
-			47,
-			58,
-			61,
-			63,
-			// numbers
-			48,
-			49,
-			50,
-			51,
-			52,
-			53,
-			54,
-			55,
-			56,
-			57,
-			// upper-case letters
-			65,
-			66,
-			67,
-			68,
-			69,
-			70,
-			71,
-			72,
-			73,
-			74,
-			75,
-			76,
-			77,
-			78,
-			79,
-			80,
-			81,
-			82,
-			83,
-			84,
-			85,
-			86,
-			87,
-			88,
-			89,
-			90,
-			// lower-case letters
-			97,
-			98,
-			99,
-			100,
-			101,
-			102,
-			103,
-			104,
-			105,
-			106,
-			107,
-			108,
-			109,
-			110,
-			111,
-			112,
-			113,
-			114,
-			115,
-			116,
-			117,
-			118,
-			119,
-			120,
-			121,
-			122,
-		];
-
-		// We are intentionally wrapping so mail servers will encode characters
-		// properly and MUAs will behave, so {unwrap} must go!
-		$str = str_replace(['{unwrap}', '{/unwrap}'], '', $str);
-
-		// RFC 2045 specifies CRLF as "\r\n".
-		// However, many developers choose to override that and violate
-		// the RFC rules due to (apparently) a bug in MS Exchange,
-		// which only works with "\n".
-		if ($this->CRLF === "\r\n")
-		{
-			return quoted_printable_encode($str);
-		}
-
-		// Reduce multiple spaces & remove nulls
-		$str = preg_replace(['| +|', '/\x00+/'], [' ', ''], $str);
-
-		// Standardize newlines
-		if (strpos($str, "\r") !== false)
-		{
-			$str = str_replace(["\r\n", "\r"], "\n", $str);
-		}
-
-		$escape = '=';
-		$output = '';
-
-		foreach (explode("\n", $str) as $line)
-		{
-			$length = static::strlen($line);
-			$temp   = '';
-
-			// Loop through each character in the line to add soft-wrap
-			// characters at the end of a line " =\r\n" and add the newly
-			// processed line(s) to the output (see comment on $crlf class property)
-			for ($i = 0; $i < $length; $i ++)
-			{
-				// Grab the next character
-				$char  = $line[$i];
-				$ascii = ord($char);
-
-				// Convert spaces and tabs but only if it's the end of the line
-				if ($ascii === 32 || $ascii === 9)
-				{
-					if ($i === ($length - 1))
-					{
-						$char = $escape . sprintf('%02s', dechex($ascii));
-					}
-				}
-				// DO NOT move this below the $ascii_safe_chars line!
-				//
-				// = (equals) signs are allowed by RFC2049, but must be encoded
-				// as they are the encoding delimiter!
-				elseif ($ascii === 61)
-				{
-					$char = $escape . strtoupper(sprintf('%02s', dechex($ascii)));  // =3D
-				}
-				elseif (! in_array($ascii, $ascii_safe_chars, true))
-				{
-					$char = $escape . strtoupper(sprintf('%02s', dechex($ascii)));
-				}
-
-				// If we're at the character limit, add the line to the output,
-				// reset our temp variable, and keep on chuggin'
-				if ((static::strlen($temp) + static::strlen($char)) >= 76)
-				{
-					$output .= $temp . $escape . $this->CRLF;
-					$temp    = '';
-				}
-
-				// Add the character to our temporary line
-				$temp .= $char;
-			}
-
-			// Add our completed line to the output
-			$output .= $temp . $this->CRLF;
-		}
-
-		// get rid of extra CRLF tacked onto the end
-		return static::substr($output, 0, static::strlen($this->CRLF) * -1);
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Prep Q Encoding
-	 *
-	 * Performs "Q Encoding" on a string for use in email headers.
-	 * It's related but not identical to quoted-printable, so it has its
-	 * own method.
-	 *
-	 * @param string $str
-	 *
-	 * @return string
-	 */
-	protected function prepQEncoding($str)
-	{
-		$str = str_replace(["\r", "\n"], '', $str);
-
-		if ($this->charset === 'UTF-8')
-		{
-			// Note: We used to have mb_encode_mimeheader() as the first choice
-			//       here, but it turned out to be buggy and unreliable. DO NOT
-			//       re-add it! -- Narf
-			if (extension_loaded('iconv'))
-			{
-				$output = @iconv_mime_encode(
-								'', $str, [
-									'scheme'           => 'Q',
-									'line-length'      => 76,
-									'input-charset'    => $this->charset,
-									'output-charset'   => $this->charset,
-									'line-break-chars' => $this->CRLF,
-								]);
-
-				// There are reports that iconv_mime_encode() might fail and return FALSE
-				if ($output !== false)
-				{
-					// iconv_mime_encode() will always put a header field name.
-					// We've passed it an empty one, but it still prepends our
-					// encoded string with ': ', so we need to strip it.
-					return static::substr($output, 2);
-				}
-
-				$chars = iconv_strlen($str, 'UTF-8');
-			}
-			elseif (extension_loaded('mbstring'))
-			{
-				$chars = mb_strlen($str, 'UTF-8');
-			}
-		}
-
-		// We might already have this set for UTF-8
-		isset($chars) || $chars = static::strlen($str);
-
-		$output = '=?' . $this->charset . '?Q?';
-		for ($i = 0, $length = static::strlen($output); $i < $chars; $i ++)
-		{
-			$chr = ($this->charset === 'UTF-8' && ICONV_ENABLED === true) ? '=' . implode('=', str_split(strtoupper(bin2hex(iconv_substr($str, $i, 1, $this->charset))), 2)) : '=' . strtoupper(bin2hex($str[$i]));
-
-			// RFC 2045 sets a limit of 76 characters per line.
-			// We'll append ?= to the end of each line though.
-			if ($length + ($l = static::strlen($chr)) > 74)
-			{
-				$output .= '?=' . $this->CRLF // EOL
-						. ' =?' . $this->charset . '?Q?' . $chr; // New line
-				$length  = 6 + static::strlen($this->charset) + $l; // Reset the length for the new line
-			}
-			else
-			{
-				$output .= $chr;
-				$length += $l;
-			}
-		}
-
-		// End the header
-		return $output . '?=';
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Send a Message
-	 *
-	 * @param Email $email
-	 *
-	 * @return boolean
-	 */
-	public function send(Email $email)
-	{
-		if (! isset($this->headers['From']) && ! empty($this->fromEmail))
-		{
-			$this->setFrom($this->fromEmail, $this->fromName);
-		}
-
-		if (! isset($this->headers['From']))
-		{
-			throw MailerException::forNoFrom();
-		}
-
-		if ($this->replyToFlag === false)
-		{
-			$this->setReplyTo($this->headers['From']);
-		}
-
-		if (empty($this->recipients) && ! isset($this->headers['To']) && empty($this->BCCArray) && ! isset($this->headers['Bcc']) && ! isset($this->headers['Cc'])
-		)
-		{
-			throw MailerException::forNoRecipients();
-		}
-
-		$this->buildHeaders();
-
-		if ($this->BCCBatchMode && count($this->BCCArray) > $this->BCCBatchSize)
-		{
-			$this->batchBCCSend();
-
-			if ($autoClear)
-			{
-				$this->clear();
-			}
-
-			return true;
-		}
-
-		$this->buildMessage();
-		$result = $this->spoolEmail();
-
-		if ($result && $autoClear)
-		{
-			$this->clear();
-		}
-
-		return $result;
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Batch Bcc Send. Sends groups of BCCs in batches
-	 */
-	public function batchBCCSend()
-	{
-		$float = $this->BCCBatchSize - 1;
-		$set   = '';
-		$chunk = [];
-
-		for ($i = 0, $c = count($this->BCCArray); $i < $c; $i ++)
-		{
-			if (isset($this->BCCArray[$i]))
-			{
-				$set .= ', ' . $this->BCCArray[$i];
-			}
-
-			if ($i === $float)
-			{
-				$chunk[] = static::substr($set, 1);
-				$float  += $this->BCCBatchSize;
-				$set     = '';
-			}
-
-			if ($i === $c - 1)
-			{
-				$chunk[] = static::substr($set, 1);
-			}
-		}
-
-		for ($i = 0, $c = count($chunk); $i < $c; $i ++)
-		{
-			unset($this->headers['Bcc']);
-
-			$bcc = $this->cleanEmail($this->stringToArray($chunk[$i]));
-
-			if ($this->protocol !== 'smtp')
-			{
-				$this->setHeader('Bcc', implode(', ', $bcc));
-			}
-			else
-			{
-				$this->BCCArray = $bcc;
-			}
-
-			$this->buildMessage();
-			$this->spoolEmail();
-		}
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Unwrap special elements
-	 */
-	protected function unwrapSpecials()
-	{
-		$this->finalBody = preg_replace_callback(
-				'/\{unwrap\}(.*?)\{\/unwrap\}/si', [
-					$this,
-					'removeNLCallback',
-				], $this->finalBody
-		);
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Strip line-breaks via callback
-	 *
-	 * @param string $matches
-	 *
-	 * @return string
-	 */
-	protected function removeNLCallback($matches)
-	{
-		if (strpos($matches[1], "\r") !== false || strpos($matches[1], "\n") !== false)
-		{
-			$matches[1] = str_replace(["\r\n", "\r", "\n"], '', $matches[1]);
-		}
-
-		return $matches[1];
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Spool mail to the mail server
-	 *
-	 * @return boolean
-	 */
-	protected function spoolEmail()
-	{
-		$this->unwrapSpecials();
-
-		$protocol = $this->getProtocol();
-		$method   = 'sendWith' . ucfirst($protocol);
-		try
-		{
-			$success = $this->$method();
-		}
-		catch (\ErrorException $e)
-		{
-			$success = false;
-			$this->logger->error('Mailer: ' . $method . ' throwed ' . $e->getMessage());
-		}
-
-		if (! $success)
-		{
-			throw MailerException::forSendFailure($protocol === 'mail' ? 'PHPMail' : ucfirst($protocol));
-		}
-
-		$this->setErrorMessage(lang('Mailer.sent', [$protocol]));
-
-		return true;
-	}
-
-	//--------------------------------------------------------------------
-
 	/**
-	 * Validate email for shell
-	 *
-	 * Applies stricter, shell-safe validation to email addresses.
-	 * Introduced to prevent RCE via sendmail's -f option.
-	 *
-	 * @see     https://github.com/codeigniter4/CodeIgniter/issues/4963
-	 * @see     https://gist.github.com/Zenexer/40d02da5e07f151adeaeeaa11af9ab36
-	 * @license https://creativecommons.org/publicdomain/zero/1.0/    CC0 1.0, Public Domain
-	 *
-	 * Credits for the base concept go to Paul Buonopane <paul@namepros.com>
-	 *
-	 * @param string &$email
+	 * Whether this handler is supported on this system.
 	 *
 	 * @return boolean
 	 */
-	protected function validateEmailForShell(&$email)
+	public function isSupported(): bool
 	{
-		if (function_exists('idn_to_ascii') && $atpos = strpos($email, '@'))
-		{
-			$email = static::substr($email, 0, ++ $atpos) . idn_to_ascii(
-							static::substr($email, $atpos), 0, INTL_IDNA_VARIANT_UTS46
-			);
-		}
-
-		return (filter_var($email, FILTER_VALIDATE_EMAIL) === $email && preg_match('#\A[a-z0-9._+-]+@[a-z0-9.-]{1,253}\z#i', $email));
+		return true;
 	}
 
-	//--------------------------------------------------------------------
-
 	/**
-	 * Send using mail()
+	 * Spools an Email to the server.
+	 *
+	 * @param Email $email
 	 *
 	 * @return boolean
 	 */
-	protected function sendWithMail()
+	protected function spool(Email $email)
 	{
-		if (is_array($this->recipients))
-		{
-			$this->recipients = implode(', ', $this->recipients);
-		}
-
-		// _validate_email_for_shell() below accepts by reference,
-		// so this needs to be assigned to a variable
-		$from = $this->cleanEmail($this->headers['Return-Path']);
-
-		if (! $this->validateEmailForShell($from))
-		{
-			return mail($this->recipients, $this->subject, $this->finalBody, $this->headerStr);
-		}
-
-		// most documentation of sendmail using the "-f" flag lacks a space after it, however
-		// we've encountered servers that seem to require it to be in place.
-		return mail($this->recipients, $this->subject, $this->finalBody, $this->headerStr, '-f ' . $from);
 	}
 
 	//--------------------------------------------------------------------
 
+/* WIP */
+
 	/**
 	 * Send using Sendmail
 	 *
@@ -1173,466 +79,4 @@ protected function sendWithSendmail()
 
 		return true;
 	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Send using SMTP
-	 *
-	 * @return boolean
-	 */
-	protected function sendWithSmtp()
-	{
-		if ($this->SMTPHost === '')
-		{
-			throw MailerException::forNoHostname();
-		}
-
-		if (! $this->SMTPConnect() || ! $this->SMTPAuthenticate())
-		{
-			return false;
-		}
-
-		if (! $this->sendCommand('from', $this->cleanEmail($this->headers['From'])))
-		{
-			$this->SMTPEnd();
-
-			return false;
-		}
-
-		foreach ($this->recipients as $val)
-		{
-			if (! $this->sendCommand('to', $val))
-			{
-				$this->SMTPEnd();
-
-				return false;
-			}
-		}
-
-		foreach ($this->CCArray as $val)
-		{
-			if ($val !== '' && ! $this->sendCommand('to', $val))
-			{
-				$this->SMTPEnd();
-
-				return false;
-			}
-		}
-
-		foreach ($this->BCCArray as $val)
-		{
-			if ($val !== '' && ! $this->sendCommand('to', $val))
-			{
-				$this->SMTPEnd();
-
-				return false;
-			}
-		}
-
-		if (! $this->sendCommand('data'))
-		{
-			$this->SMTPEnd();
-
-			return false;
-		}
-
-		// perform dot transformation on any lines that begin with a dot
-		$this->sendData($this->headerStr . preg_replace('/^\./m', '..$1', $this->finalBody));
-
-		$this->sendData('.');
-		$reply = $this->getSMTPData();
-		$this->setErrorMessage($reply);
-
-		$this->SMTPEnd();
-
-		if (strpos($reply, '250') !== 0)
-		{
-			throw MailerException::forSMTPError($reply);
-		}
-
-		return true;
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * SMTP End
-	 *
-	 * Shortcut to send RSET or QUIT depending on keep-alive
-	 */
-	protected function SMTPEnd()
-	{
-		$this->sendCommand($this->SMTPKeepAlive ? 'reset' : 'quit');
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * SMTP Connect
-	 *
-	 * @return string
-	 */
-	protected function SMTPConnect()
-	{
-		if (is_resource($this->SMTPConnect))
-		{
-			return true;
-		}
-
-		$ssl = ($this->SMTPCrypto === 'ssl') ? 'ssl://' : '';
-
-		$this->SMTPConnect = fsockopen(
-				$ssl . $this->SMTPHost, $this->SMTPPort, $errno, $errstr, $this->SMTPTimeout
-		);
-
-		if (! is_resource($this->SMTPConnect))
-		{
-			throw MailerException::forSMTPError($errno . ' ' . $errstr);
-		}
-
-		stream_set_timeout($this->SMTPConnect, $this->SMTPTimeout);
-		$this->setErrorMessage($this->getSMTPData());
-
-		if ($this->SMTPCrypto === 'tls')
-		{
-			$this->sendCommand('hello');
-			$this->sendCommand('starttls');
-
-			$crypto = stream_socket_enable_crypto($this->SMTPConnect, true, STREAM_CRYPTO_METHOD_TLS_CLIENT);
-
-			if ($crypto !== true)
-			{
-				throw MailerException::forSMTPError($this->getSMTPData());
-			}
-		}
-
-		return $this->sendCommand('hello');
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Send SMTP command
-	 *
-	 * @param string $cmd
-	 * @param string $data
-	 *
-	 * @return boolean
-	 */
-	protected function sendCommand($cmd, $data = '')
-	{
-		switch ($cmd)
-		{
-			case 'hello':
-				if ($this->SMTPAuth || $this->getEncoding() === '8bit')
-				{
-					$this->sendData('EHLO ' . $this->getHostname());
-				}
-				else
-				{
-					$this->sendData('HELO ' . $this->getHostname());
-				}
-
-				$resp = 250;
-				break;
-			case 'starttls':
-				$this->sendData('STARTTLS');
-				$resp = 220;
-				break;
-			case 'from':
-				$this->sendData('MAIL FROM:<' . $data . '>');
-				$resp = 250;
-				break;
-			case 'to':
-				if ($this->DSN)
-				{
-					$this->sendData('RCPT TO:<' . $data . '> NOTIFY=SUCCESS,DELAY,FAILURE ORCPT=rfc822;' . $data);
-				}
-				else
-				{
-					$this->sendData('RCPT TO:<' . $data . '>');
-				}
-				$resp = 250;
-				break;
-			case 'data':
-				$this->sendData('DATA');
-				$resp = 354;
-				break;
-			case 'reset':
-				$this->sendData('RSET');
-				$resp = 250;
-				break;
-			case 'quit':
-				$this->sendData('QUIT');
-				$resp = 221;
-				break;
-		}
-
-		$reply = $this->getSMTPData();
-
-		$this->debugMessage[] = '<pre>' . $cmd . ': ' . $reply . '</pre>';
-
-		if ((int) static::substr($reply, 0, 3) !== $resp)
-		{
-			throw MailerException::forSMTPError($reply);
-		}
-
-		if ($cmd === 'quit')
-		{
-			fclose($this->SMTPConnect);
-		}
-
-		return true;
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * SMTP Authenticate
-	 *
-	 * @return boolean
-	 */
-	protected function SMTPAuthenticate()
-	{
-		if (! $this->SMTPAuth)
-		{
-			return true;
-		}
-
-		if ($this->SMTPUser === '' && $this->SMTPPass === '')
-		{
-			throw MailerException::forNoSMTPAuth();
-		}
-
-		$this->sendData('AUTH LOGIN');
-		$reply = $this->getSMTPData();
-
-		if (strpos($reply, '503') === 0)    // Already authenticated
-		{
-			return true;
-		}
-		elseif (strpos($reply, '334') !== 0)
-		{
-			throw MailerException::forFailedSMTPLogin($reply);
-		}
-
-		$this->sendData(base64_encode($this->SMTPUser));
-		$reply = $this->getSMTPData();
-
-		if (strpos($reply, '334') !== 0)
-		{
-			throw MailerException::forSMTPAuthUsername($reply);
-		}
-
-		$this->sendData(base64_encode($this->SMTPPass));
-		$reply = $this->getSMTPData();
-
-		if (strpos($reply, '235') !== 0)
-		{
-			throw MailerException::forSMTPAuthPassword($reply);
-		}
-
-		if ($this->SMTPKeepAlive)
-		{
-			$this->SMTPAuth = false;
-		}
-
-		return true;
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Send SMTP data
-	 *
-	 * @param string $data
-	 *
-	 * @return boolean
-	 */
-	protected function sendData($data)
-	{
-		$data .= $this->newline;
-		for ($written = $timestamp = 0, $length = static::strlen($data); $written < $length; $written += $result)
-		{
-			if (($result = fwrite($this->SMTPConnect, static::substr($data, $written))) === false)
-			{
-				break;
-			}
-			// See https://bugs.php.net/bug.php?id=39598 and http://php.net/manual/en/function.fwrite.php#96951
-			elseif ($result === 0)
-			{
-				if ($timestamp === 0)
-				{
-					$timestamp = time();
-				}
-				elseif ($timestamp < (time() - $this->SMTPTimeout))
-				{
-					$result = false;
-					break;
-				}
-
-				usleep(250000);
-				continue;
-			}
-			else
-			{
-				$timestamp = 0;
-			}
-		}
-
-		if ($result === false)
-		{
-			throw MailerException::forSMTPDataFailure($data);
-		}
-
-		return true;
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Get SMTP data
-	 *
-	 * @return string
-	 */
-	protected function getSMTPData()
-	{
-		$data = '';
-
-		while ($str = fgets($this->SMTPConnect, 512))
-		{
-			$data .= $str;
-
-			if ($str[3] === ' ')
-			{
-				break;
-			}
-		}
-
-		return $data;
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Get Hostname
-	 *
-	 * There are only two legal types of hostname - either a fully
-	 * qualified domain name (eg: "mail.example.com") or an IP literal
-	 * (eg: "[1.2.3.4]").
-	 *
-	 * @link https://tools.ietf.org/html/rfc5321#section-2.3.5
-	 * @link http://cbl.abuseat.org/namingproblems.html
-	 *
-	 * @return string
-	 */
-	protected function getHostname()
-	{
-		if (isset($_SERVER['SERVER_NAME']))
-		{
-			return $_SERVER['SERVER_NAME'];
-		}
-
-		return isset($_SERVER['SERVER_ADDR']) ? '[' . $_SERVER['SERVER_ADDR'] . ']' : '[127.0.0.1]';
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Get Debug Message
-	 *
-	 * @param array $include List of raw data chunks to include in the output
-	 *                       Valid options are: 'headers', 'subject', 'body'
-	 *
-	 * @return string
-	 */
-	public function printDebugger($include = ['headers', 'subject', 'body'])
-	{
-		$msg = implode('', $this->debugMessage);
-
-		// Determine which parts of our raw data needs to be printed
-		$raw_data                      = '';
-		is_array($include) || $include = [$include];
-
-		in_array('headers', $include, true) && $raw_data  = htmlspecialchars($this->headerStr) . "\n";
-		in_array('subject', $include, true) && $raw_data .= htmlspecialchars($this->subject) . "\n";
-		in_array('body', $include, true) && $raw_data    .= htmlspecialchars($this->finalBody);
-
-		return $msg . ($raw_data === '' ? '' : '<pre>' . $raw_data . '</pre>');
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Set Message
-	 *
-	 * @param string $msg
-	 */
-	protected function setErrorMessage($msg)
-	{
-		$this->debugMessage[] = $msg . '<br />';
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Mime Types
-	 *
-	 * @param string $ext
-	 *
-	 * @return string
-	 */
-	protected function mimeTypes($ext = '')
-	{
-		$mime = Mimes::guessTypeFromExtension(strtolower($ext));
-
-		return ! empty($mime) ? $mime : 'application/x-unknown-content-type';
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Destructor
-	 */
-	public function __destruct()
-	{
-		is_resource($this->SMTPConnect) && $this->sendCommand('quit');
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Byte-safe strlen()
-	 *
-	 * @param string $str
-	 *
-	 * @return integer
-	 */
-	protected static function strlen($str)
-	{
-		return (static::$func_overload) ? mb_strlen($str, '8bit') : strlen($str);
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Byte-safe substr()
-	 *
-	 * @param string       $str
-	 * @param integer      $start
-	 * @param integer|null $length
-	 *
-	 * @return string
-	 */
-	protected static function substr($str, $start, $length = null)
-	{
-		if (static::$func_overload)
-		{
-			return mb_substr($str, $start, $length, '8bit');
-		}
-
-		return isset($length) ? substr($str, $start, $length) : substr($str, $start);
-	}
-
 }

From 31028bb035ee8961d265d6e29e7bbef9f906c0bf Mon Sep 17 00:00:00 2001
From: MGatner <mgatner@icloud.com>
Date: Mon, 25 Apr 2022 13:34:06 +0000
Subject: [PATCH 6/8] Apply updated coding standard

---
 system/Config/Services.php                   |   24 +-
 system/Language/en/Mailer.php                |   52 +-
 system/Mailer/Address.php                    |  276 +-
 system/Mailer/Attachment.php                 |  152 +-
 system/Mailer/Email.php                      |  923 +++---
 system/Mailer/Encode.php                     |  530 ++-
 system/Mailer/Exceptions/MailerException.php |  244 +-
 system/Mailer/Format.php                     |    6 +-
 system/Mailer/Handlers/BaseHandler.php       |  719 ++---
 system/Mailer/Handlers/DummyHandler.php      |   40 +-
 system/Mailer/Handlers/MailHandler.php       |  175 +-
 system/Mailer/Handlers/SMTPHandler.php       | 3016 +++++++++---------
 system/Mailer/Handlers/SendmailHandler.php   |  105 +-
 system/Mailer/MailerInterface.php            |   36 +-
 14 files changed, 2961 insertions(+), 3337 deletions(-)

diff --git a/system/Config/Services.php b/system/Config/Services.php
index e20192cda744..cc9a50669d35 100644
--- a/system/Config/Services.php
+++ b/system/Config/Services.php
@@ -71,7 +71,7 @@
 use Config\Format as FormatConfig;
 use Config\Honeypot as HoneypotConfig;
 use Config\Images;
-use Config\Mailer as Mailer;
+use Config\Mailer;
 use Config\Migrations;
 use Config\Pager as PagerConfig;
 use Config\Services as AppServices;
@@ -385,27 +385,19 @@ public static function logger(bool $getShared = true)
         return new Logger(config('Logger'));
     }
 
-    //--------------------------------------------------------------------
-
     /**
      * The Mailer class sends emails from any of the available protocol handlers.
      *
-     * @param Mailer|null $config
-     * @param boolean $getShared
-     *
-     * @return MailerInterface
-     *
      * @throws MailerException
      */
-    public static function mailer(Mailer $config = null, bool $getShared = true): MailerInterface
+    public static function mailer(?Mailer $config = null, bool $getShared = true): MailerInterface
     {
-        if ($getShared)
-        {
+        if ($getShared) {
             return static::getSharedInstance('mailer', $config);
         }
 
         // Use Factories to load the default handler
-        $config  = $config ?? config('Mailer');
+        $config ??= config('Mailer');
         $handler = ucfirst($config->handler) . 'Handler';
         $options = [
             'path'       => 'Mailer/Handlers',
@@ -414,20 +406,16 @@ public static function mailer(Mailer $config = null, bool $getShared = true): Ma
             'preferApp'  => true,
         ];
 
-        if (! $mailer = Factories::mailer($handler, $options, $config))
-        {
+        if (! $mailer = Factories::mailer($handler, $options, $config)) {
             throw MailerException::forHandlerNotFound();
         }
-        if (! $mailer->isSupported())
-        {
+        if (! $mailer->isSupported()) {
             throw MailerException::forHandlerNotSupported(get_class($mailer));
         }
 
         return $mailer;
     }
 
-    //--------------------------------------------------------------------
-
     /**
      * Return the appropriate Migration runner.
      *
diff --git a/system/Language/en/Mailer.php b/system/Language/en/Mailer.php
index c4f8b0a1ec60..3546b72ea669 100644
--- a/system/Language/en/Mailer.php
+++ b/system/Language/en/Mailer.php
@@ -1,38 +1,38 @@
 <?php
 
 /**
- * This file is part of the CodeIgniter 4 framework.
+ * This file is part of CodeIgniter 4 framework.
  *
  * (c) CodeIgniter Foundation <admin@codeigniter.com>
  *
- * For the full copyright and license information, please view the LICENSE
- * file that was distributed with this source code.
+ * For the full copyright and license information, please view
+ * the LICENSE file that was distributed with this source code.
  */
 
 return [
-	'handlerNotFound'     => 'Mailer config has an invalid or missing handler.',
-	'handlerNotSupported' => '{0} is not supported on your system.',
-	'invalidAddress'      => 'Invalid email address: {0}',
-	'noFrom'              => 'Cannot send mail with no "From" header.',
-	'noRecipients'        => 'You must include recipients: To, Cc, or Bcc',
-	'mimeMessage'         => 'This is a multi-part message in MIME format.{0}Your email application may not support this format.',
+    'handlerNotFound'     => 'Mailer config has an invalid or missing handler.',
+    'handlerNotSupported' => '{0} is not supported on your system.',
+    'invalidAddress'      => 'Invalid email address: {0}',
+    'noFrom'              => 'Cannot send mail with no "From" header.',
+    'noRecipients'        => 'You must include recipients: To, Cc, or Bcc',
+    'mimeMessage'         => 'This is a multi-part message in MIME format.{0}Your email application may not support this format.',
 
-/*
-	'mustBeArray'          => 'The email validation method must be passed an array.',
-	'attachmentMissing'    => 'Unable to locate the following email attachment: {0}',
-	'attachmentUnreadable' => 'Unable to open this attachment: {0}',
-	'sendFailurePHPMail'   => 'Unable to send email using PHP mail(). Your server might not be configured to send mail using this method.',
-	'sendFailureSendmail'  => 'Unable to send email using PHP Sendmail. Your server might not be configured to send mail using this method.',
-	'sendFailureSmtp'      => 'Unable to send email using PHP SMTP. Your server might not be configured to send mail using this method.',
-	'sent'                 => 'Your message has been successfully sent using the following protocol: {0}',
-	'noSocket'             => 'Unable to open a socket to Sendmail. Please check settings.',
-	'noHostname'           => 'You did not specify a SMTP hostname.',
-	'SMTPError'            => 'The following SMTP error was encountered: {0}',
-	'noSMTPAuth'           => 'Error: You must assign a SMTP username and password.',
-	'failedSMTPLogin'      => 'Failed to send AUTH LOGIN command. Error: {0}',
-	'SMTPAuthUsername'     => 'Failed to authenticate username. Error: {0}',
-	'SMTPAuthPassword'     => 'Failed to authenticate password. Error: {0}',
-	'SMTPDataFailure'      => 'Unable to send data: {0}',
-	'exitStatus'           => 'Exit status code: {0}',
+    /*
+    'mustBeArray'          => 'The email validation method must be passed an array.',
+    'attachmentMissing'    => 'Unable to locate the following email attachment: {0}',
+    'attachmentUnreadable' => 'Unable to open this attachment: {0}',
+    'sendFailurePHPMail'   => 'Unable to send email using PHP mail(). Your server might not be configured to send mail using this method.',
+    'sendFailureSendmail'  => 'Unable to send email using PHP Sendmail. Your server might not be configured to send mail using this method.',
+    'sendFailureSmtp'      => 'Unable to send email using PHP SMTP. Your server might not be configured to send mail using this method.',
+    'sent'                 => 'Your message has been successfully sent using the following protocol: {0}',
+    'noSocket'             => 'Unable to open a socket to Sendmail. Please check settings.',
+    'noHostname'           => 'You did not specify a SMTP hostname.',
+    'SMTPError'            => 'The following SMTP error was encountered: {0}',
+    'noSMTPAuth'           => 'Error: You must assign a SMTP username and password.',
+    'failedSMTPLogin'      => 'Failed to send AUTH LOGIN command. Error: {0}',
+    'SMTPAuthUsername'     => 'Failed to authenticate username. Error: {0}',
+    'SMTPAuthPassword'     => 'Failed to authenticate password. Error: {0}',
+    'SMTPDataFailure'      => 'Unable to send data: {0}',
+    'exitStatus'           => 'Exit status code: {0}',
 */
 ];
diff --git a/system/Mailer/Address.php b/system/Mailer/Address.php
index 0039ba08a944..b809dfb4d80d 100644
--- a/system/Mailer/Address.php
+++ b/system/Mailer/Address.php
@@ -1,12 +1,12 @@
 <?php
 
 /**
- * This file is part of the CodeIgniter 4 framework.
+ * This file is part of CodeIgniter 4 framework.
  *
  * (c) CodeIgniter Foundation <admin@codeigniter.com>
  *
- * For the full copyright and license information, please view the LICENSE
- * file that was distributed with this source code.
+ * For the full copyright and license information, please view
+ * the LICENSE file that was distributed with this source code.
  */
 
 namespace CodeIgniter\Mailer;
@@ -15,150 +15,128 @@
 
 class Address
 {
-	/**
-	 * Characters to trim from display names.
-	 */
-	private const TRIM = ' \'"';
-
-	/**
-	 * @var string
-	 */
-	protected $email;
-
-	/**
-	 * @var string
-	 */
-	protected $name;
-
-	/**
-	 * Creates a new Address from a simple or full email address string.
-	 *
-	 * @param string $address
-	 *
-	 * @return static
-	 */
-	public static function create(string $address)
-	{
-		return new static(...array_values(self::split($address)));
-	}
-
-	/**
-	 * Creates an array of Addresses from an array of inputs.
-	 * Accounts for the niche case of a single CSV of addresses
-	 * @see Email::to()
-	 *
-	 * @param string[] $addresses
-	 *
-	 * @return static[]
-	 */
-	public static function createArray(array $addresses)
-	{
-    	// Check for a CSV first
-    	if (count($addresses) === 1)
-    	{
-    		$element = reset($addresses);
-
-    		if (is_string($element) && strpos($element, ',') !== false)
-	    	{
-    			$addresses = preg_split('/[\s,]/', $element, -1, PREG_SPLIT_NO_EMPTY);
-    		}
-    	}
-
-		return array_map('self::create', $addresses);
-	}
-
-
-	/**
-	 * Parses an address into an email and (optional) display name.
-	 * Trims content but does no validation or encoding.
-	 *
-	 * @param string $address
-	 */
-	final public static function split(string $address): array
-	{
-		if (preg_match('/\<(.*)\>/', $address, $matches))
-		{
-			return [
-				'email' => trim($matches[1]),
-				'name'  => trim(substr($address, 0, -1 * strlen($matches[0])), self::TRIM),
-			];
-		}
-
-		return [
-			'email' => trim($address),
-			'name'  => null,
-		];
-	}
-
-	/**
-	 * Combines an email and (optional) display name into an address
-	 * with wrapping quotes and angle brackets.
-	 * Trims content but does no validation or encoding.
-	 *
-	 * @param string $email
-	 * @param string|null $name
-	 */
-	final public static function merge(string $email, string $name = null): string
-	{
-		if (is_null($name))
-		{
-			return trim($email);
-		}
-
-		// Enclose the email in angle brackets
-		$email = '<' . $email . '>';
-
-		// If there is no name then finish
-		if ('' === $name = trim($name, SELF::TRIM))
-		{
-			return $email;
-		}
-
-		// Wrap the name in quotes and prepend it to the email
-		return '"' . $name . '" ' . $email;
-	}
-
-	/**
-	 * Validates the email and stores the values.
-	 *
-	 * @param string $email
-	 * @param string|null $name
-	 *
-	 * @throws MailerException
-	 */
-	final public function __construct(string $email, string $name = null)
-	{
-		$this->email = trim($email);
-
-		if (! service('validation')->check($this->email, 'required|valid_email'))
-		{
-			throw MailerException::forInvalidAddress($email);
-		}
-
-		$this->name = isset($name) ? trim($name, self::TRIM) : null;
-	}
-
-	/**
-	 * @return string
-	 */
-	public function getEmail(): string
-	{
-		return $this->email;
-	}
-
-	/**
-	 * @return string|null $name
-	 */
-	public function getName(): ?string
-	{
-		return $this->name;
-	}
-
-	/**
-	 * @return string
-	 */
-	public function __toString(): string
-	{
-		return self::merge($this->email, $this->name);
-	}
+    /**
+     * Characters to trim from display names.
+     */
+    private const TRIM = ' \'"';
+
+    /**
+     * @var string
+     */
+    protected $email;
+
+    /**
+     * @var string
+     */
+    protected $name;
+
+    /**
+     * Creates a new Address from a simple or full email address string.
+     *
+     * @return static
+     */
+    public static function create(string $address)
+    {
+        return new static(...array_values(self::split($address)));
+    }
+
+    /**
+     * Creates an array of Addresses from an array of inputs.
+     * Accounts for the niche case of a single CSV of addresses
+     *
+     * @see Email::to()
+     *
+     * @param string[] $addresses
+     *
+     * @return static[]
+     */
+    public static function createArray(array $addresses)
+    {
+        // Check for a CSV first
+        if (count($addresses) === 1) {
+            $element = reset($addresses);
+
+            if (is_string($element) && strpos($element, ',') !== false) {
+                $addresses = preg_split('/[\s,]/', $element, -1, PREG_SPLIT_NO_EMPTY);
+            }
+        }
+
+        return array_map('self::create', $addresses);
+    }
+
+    /**
+     * Parses an address into an email and (optional) display name.
+     * Trims content but does no validation or encoding.
+     */
+    final public static function split(string $address): array
+    {
+        if (preg_match('/\<(.*)\>/', $address, $matches)) {
+            return [
+                'email' => trim($matches[1]),
+                'name'  => trim(substr($address, 0, -1 * strlen($matches[0])), self::TRIM),
+            ];
+        }
+
+        return [
+            'email' => trim($address),
+            'name'  => null,
+        ];
+    }
+
+    /**
+     * Combines an email and (optional) display name into an address
+     * with wrapping quotes and angle brackets.
+     * Trims content but does no validation or encoding.
+     */
+    final public static function merge(string $email, ?string $name = null): string
+    {
+        if (null === $name) {
+            return trim($email);
+        }
+
+        // Enclose the email in angle brackets
+        $email = '<' . $email . '>';
+
+        // If there is no name then finish
+        if ('' === $name = trim($name, self::TRIM)) {
+            return $email;
+        }
+
+        // Wrap the name in quotes and prepend it to the email
+        return '"' . $name . '" ' . $email;
+    }
+
+    /**
+     * Validates the email and stores the values.
+     *
+     * @throws MailerException
+     */
+    final public function __construct(string $email, ?string $name = null)
+    {
+        $this->email = trim($email);
+
+        if (! service('validation')->check($this->email, 'required|valid_email')) {
+            throw MailerException::forInvalidAddress($email);
+        }
+
+        $this->name = isset($name) ? trim($name, self::TRIM) : null;
+    }
+
+    public function getEmail(): string
+    {
+        return $this->email;
+    }
+
+    /**
+     * @return string|null $name
+     */
+    public function getName(): ?string
+    {
+        return $this->name;
+    }
+
+    public function __toString(): string
+    {
+        return self::merge($this->email, $this->name);
+    }
 }
diff --git a/system/Mailer/Attachment.php b/system/Mailer/Attachment.php
index 778c371c07a2..b0cbba9bc89e 100644
--- a/system/Mailer/Attachment.php
+++ b/system/Mailer/Attachment.php
@@ -1,12 +1,12 @@
 <?php
 
 /**
- * This file is part of the CodeIgniter 4 framework.
+ * This file is part of CodeIgniter 4 framework.
  *
  * (c) CodeIgniter Foundation <admin@codeigniter.com>
  *
- * For the full copyright and license information, please view the LICENSE
- * file that was distributed with this source code.
+ * For the full copyright and license information, please view
+ * the LICENSE file that was distributed with this source code.
  */
 
 namespace CodeIgniter\Mailer;
@@ -22,89 +22,85 @@
  */
 class Attachment extends File
 {
-	/**
-	 * Whether the disposition should be 'inline' (versus 'attachment')
-	 *
-	 * @var bool
-	 */
-	protected $inline;
+    /**
+     * Whether the disposition should be 'inline' (versus 'attachment')
+     *
+     * @var bool
+     */
+    protected $inline;
 
-	/**
-	 * The name to use when sending the file. Defaults to the basename.
-	 *
-	 * @var string
-	 */
-	protected $name;
+    /**
+     * The name to use when sending the file. Defaults to the basename.
+     *
+     * @var string
+     */
+    protected $name;
 
-	/**
-	 * The current ID to link to this attachment.
-	 * E.g. for inline pictures.
-	 *
-	 * @var string|null
-	 */
-	protected $contentId;
+    /**
+     * The current ID to link to this attachment.
+     * E.g. for inline pictures.
+     *
+     * @var string|null
+     */
+    protected $contentId;
 
-	/**
-	 * Verifies local files and stores the values.
-	 *
-	 * @param string $path
-	 * @param bool $inline      Whether the disposition should be 'inline' (versus 'attachment')
-	 * @param string|null $name An alternate name to use
-	 *
-	 * @throws FileNotFoundException
-	 */
-	public function __construct(string $path, bool $inline = false, string $name = null)
-	{
-		parent::__construct($path, strpos($path, '://') === false);
+    /**
+     * Verifies local files and stores the values.
+     *
+     * @param bool        $inline Whether the disposition should be 'inline' (versus 'attachment')
+     * @param string|null $name   An alternate name to use
+     *
+     * @throws FileNotFoundException
+     */
+    public function __construct(string $path, bool $inline = false, ?string $name = null)
+    {
+        parent::__construct($path, strpos($path, '://') === false);
 
-		$this->inline = $inline;
-		$this->name   = $name ?? $this->getFilename();
-	}
+        $this->inline = $inline;
+        $this->name   = $name ?? $this->getFilename();
+    }
 
-	/**
-	 * Whether this Attachment has a Content-ID set.
-	 *
-	 * @return boolean
-	 */
-	public function hasContentId(): bool
-	{
-		return isset($this->contentId);
-	}
+    /**
+     * Whether this Attachment has a Content-ID set.
+     */
+    public function hasContentId(): bool
+    {
+        return isset($this->contentId);
+    }
 
-	/**
-	 * Creates and returns a Content-ID
-	 * E.g. for inline pictures.
-	 *
-	 * @param string $filename
-	 *
-	 * @return string|boolean
-	 */
-	public function getContentId()
-	{
-		if (is_null($this->contentId))
-		{
-			$this->contentId = uniqid($this->name . '@', true);
-		}
+    /**
+     * Creates and returns a Content-ID
+     * E.g. for inline pictures.
+     *
+     * @param string $filename
+     *
+     * @return bool|string
+     */
+    public function getContentId()
+    {
+        if (null === $this->contentId) {
+            $this->contentId = uniqid($this->name . '@', true);
+        }
 
-		return $this->contentId;
-	}
+        return $this->contentId;
+    }
 
-	/**
-	 * Returns the file content ready for spooling.
-	 *
-	 * @return string
-	 *
-	 * @throws RuntimeException For open/access errors
-	 */
-	public function getContent(): bool
-	{
-		// Read in the binary data
-		$file = $this->openFile('rb');
-		$file->rewind();
+    /**
+     * Returns the file content ready for spooling.
+     *
+     * @throws RuntimeException For open/access errors
+     *
+     * @return string
+     */
+    public function getContent(): bool
+    {
+        // Read in the binary data
+        $file = $this->openFile('rb');
+        $file->rewind();
 
-		$content = $file->fread($file->getSize());
-		unset($file);		
+        $content = $file->fread($file->getSize());
+        unset($file);
 
-		return chunk_split(base64_encode($content));
-	}
+        return chunk_split(base64_encode($content));
+    }
 }
diff --git a/system/Mailer/Email.php b/system/Mailer/Email.php
index eeda990c2553..d0d20b675c7f 100644
--- a/system/Mailer/Email.php
+++ b/system/Mailer/Email.php
@@ -1,19 +1,19 @@
 <?php
 
 /**
- * This file is part of the CodeIgniter 4 framework.
+ * This file is part of CodeIgniter 4 framework.
  *
  * (c) CodeIgniter Foundation <admin@codeigniter.com>
  *
- * For the full copyright and license information, please view the LICENSE
- * file that was distributed with this source code.
+ * For the full copyright and license information, please view
+ * the LICENSE file that was distributed with this source code.
  */
 
 namespace CodeIgniter\Mailer;
 
 use BadMethodCallException;
-use CodeIgniter\I18n\Time;
 use CodeIgniter\HTTP\Message;
+use CodeIgniter\I18n\Time;
 use DateTimeInterface;
 
 /**
@@ -24,493 +24,430 @@
  */
 class Email extends Message
 {
-	/**
-	 * Array of priorities and their encoded value.
-	 */
-	private const PRIORITIES = [
-		1 => '1 (Highest)',
-		2 => '2 (High)',
-		3 => '3 (Normal)',
-		4 => '4 (Low)',
-		5 => '5 (Lowest)',
-	];
-
-	/**
-	 * Array of Headers to collapse into a CSV.
-	 */
-	private const CSV_HEADERS = ['To', 'Cc', 'Bcc'];
-
-	/**
-	 * Attachments to this email
-	 *
-	 * @var Attachment[]
-	 */
-	protected $attachements = [];
-
-	/**
-	 * This email's unique Message ID.
-	 *
-	 * @var string|null
-	 */
-	private $messageId;
-
-	/**
-	 * Boundaries for header & body divisions.
-	 *
-	 * @var array<string,string>
-	 */
-	private $boundaries = [];
-
-	/**
-	 * Stores any initial values.
-	 *
-	 * @param array $data
-	 */
-	public function __construct(array $data = [])
-	{
-		$this->set($data);
-	}
-
-	/**
-	 * Resets $messageId for clones to ensure each is unique.
-	 */
-	public function __clone()
-	{
-		unset($this->messageId);
-	}
-
-	//--------------------------------------------------------------------
-	// Class Operations
-	//--------------------------------------------------------------------
-
-	/**
-	 * Bulk stores values by matching input keys to their setter method.
-	 *
-	 * @param array $data
-	 * @param boolean $overwrite
-	 *
-	 * @return $this
-	 */
-	public function set(array $data, bool $overwrite = true): self
-	{
-		// Check for matching keys
-		foreach ([
-			'body',
-			'subject',
-			'from',
-			'to',
-			'cc',
-			'bcc',
-			'replyTo',
-			'returnPath',
-			'priority',
-			'date',			
-		] as $setter)
-		{
-			$getter = 'get' . ucfirst($setter);
-
-			if (array_key_exists($setter, $data))
-			{
-				if ($overwrite || is_null($this->$getter()))
-				{
-					$this->$method($data[$method]);
-				}
-			}
-		}
-
-		return $this;
-	}
-
-	/**
-	 * Compiles headers into a spool-ready string.
-	 *
-	 * @param string $newline        Character(s) to use when combining the sequence
-	 * @param string[]|null $exclude An array of header names to exclude
-	 * @param string[]|null $include An array of header names to include
-	 *
-	 * @return string
-	 */
-	public function getHeaderString(string $newline = "\r\n", array $exclude = null, array $include = null): string
-	{
-		$string = '';
-
-		// Use $headers directly instead of headers() so as not to trigger populateHeaders()
-		foreach ($this->headers as $name => $value)
-		{
-			// Check exclusion
-			if (isset($exclude) && in_array($name, $exclude))
-			{
-				continue;
-			}
-			// Check includion
-			if (isset($include) && ! in_array($name, $include))
-			{
-				continue;
-			}
-
-			// Check for a collapsible
-			if (in_array($name, self::CSV_HEADERS) && is_array($value))
-			{
-				$string .= implode(',', array_map('__toString', $value));
-			}
-			elseif (is_array($value))
-			{
-				foreach ($value as $header)
-				{
-					$string .= $header . $this->newline;
-				}
-			}
-			else
-			{
-				$string .= $value . $this->newline; // Trailing newline is intentional
-			}
-		}
-	}
-
-	//--------------------------------------------------------------------
-	// Setters
-	//--------------------------------------------------------------------
-
-	/**
-	 * Intercepts calls to Message::setBody() to enforce formatting.
-	 *
-	 * @param string $body
-	 *
-	 * @return $this
-	 */
-	public function setBody($body): self
-	{
-		return $this->body($body);
-	}
-
-	/**
-	 * @param string $body
-	 *
-	 * @return $this
-	 */
-	public function body(string $body)
-	{
-		return parent::setBody(rtrim(str_replace("\r", '', $body)));
-	}
-
-	/**
-	 * @param string $subject
-	 *
-	 * @return $this
-	 */
-	public function subject(string $subject)
-	{
-	    return $this->setHeader('Subject', $subject);
-	}
-
-	/**
-	 * @param string $address
-	 *
-	 * @return $this
-	 */
-	public function from(string $address)
-	{
-	    return $this->setHeader('From', Address::create($address));
-	}
-
-	/**
-	 * @param Address|string ...$addresses
-	 *
-	 * @return $this
-	 */
-	public function to(...$addresses)
-	{
-	    return $this->setHeader('To', Address::createArray($addresses));
-	}
-
-	/**
-	 * @param Address|string ...$addresses
-	 *
-	 * @return $this
-	 */
-	public function cc(...$addresses)
-	{
-	    return $this->setHeader('Cc', Address::createArray($addresses));
-	}
-
-	/**
-	 * @param Address|string ...$addresses
-	 *
-	 * @return $this
-	 */
-	public function bcc(...$addresses)
-	{
-	    return $this->setHeader('Bcc', Address::createArray($addresses));
-	}
-
-	/**
-	 * @param string $address
-	 *
-	 * @return $this
-	 */
-	public function replyTo(string $address)
-	{
-	    return $this->setHeader('From', Address::create($address));
-	}
-
-	/**
-	 * Return-Path must be only an email enclosed in angle brackets, e.g. "<admin@codeigniter.com>"
-	 *
-	 * @param string $address
-	 *
-	 * @return $this
-	 */
-	public function returnPath(string $address)
-	{
-		// Force Address to use angle braces by giving an empty display name
-		$email = Address::split($address)['email'];
-
-	    return $this->setHeader('Return-Path', new Address($email, ''));
-	}
-
-	/**
-	 * Sets the priority, where 1 is the highest and 5 is the lowest.
-	 *
-	 * @param int $priority
-	 *
-	 * @return $this
-	 */
-	public function priority(int $priority)
-	{
-		$priority = max($priority, 1);
-		$priority = min($priority, 5);
-
-	    return $this->setHeader('X-Priority', self::PRIORITIES[$priority]);
-	}
-
-	/**
-	 * @return $this
-	 */
-	public function date(DateTimeInterface $date)
-	{
-		return $this->setHeader('Date', (string) Time::createFromInstance($date));
-	}
-
-	//--------------------------------------------------------------------
-	// Getters
-	//--------------------------------------------------------------------
-
-	/**
-	 * @return string|null
-	 */
-	public function getSubject(): ?string
-	{
-		return $this->hasHeader('Subject') ? $this->getHeader('Subject')->getValue() : null;
-	}
-
-	/**
-	 * @return Address|null
-	 */
-	public function getFrom(): ?Address
-	{
-		return $this->hasHeader('From') ? Address::create($this->getHeader('From')->getValue()) : null;
-	}
-
-	/**
-	 * @return Address[]|null
-	 */
-	public function getTo(): ?array
-	{
-		return $this->hasHeader('To') ? Address::createArray($this->getHeader('To')->getValue()) : null;
-	}
-
-	/**
-	 * @return Address[]|null
-	 */
-	public function getCc(): ?array
-	{
-		return $this->hasHeader('Cc') ? Address::createArray($this->getHeader('Cc')->getValue()) : null;
-	}
-
-	/**
-	 * @return Address[]|null
-	 */
-	public function getBcc(): ?array
-	{
-		return $this->hasHeader('Bcc') ? Address::createArray($this->getHeader('Bcc')->getValue()) : null;
-	}
-
-	/**
-	 * @return Address|null
-	 */
-	public function getReplyTo(): ?Address
-	{
-		return $this->hasHeader('Reply-To') ? Address::create($this->getHeader('Reply-To')->getValue()) : null;
-	}
-
-	/**
-	 * @return Address|null
-	 */
-	public function getReturnPath(): ?Address
-	{
-		if (! $this->hasHeader('Return-Path'))
-		{
-			return null;
-		}
-
-		// Get just the email portion of the stored address
-		$address = $this->getHeader('Return-Path')->getValue();
-		$email   = Address::split($address)['email'];
-
-		// Force Address to use angle braces by giving an empty display name
-	    return new Address($email, '');
-	}
-
-	/**
-	 * Returns the priority as an integer parsed from the header,
-	 * where 1 is the highest and 5 is the lowest.
-	 *
-	 * @return int
-	 */
-	public function getPriority(): ?int
-	{
-		if ($this->hasHeader('X-Priority'))
-		{
-			return array_search($this->getHeader('X-Priority')->getValue(), self::PRIORITIES, true) ?: null;
-		}
-
-		return null;
-	}
-
-	/**
-	 * @return Time|null
-	 */
-	public function getDate(): ?Time
-	{
-		return $this->hasHeader('Date') ? Time::parse($this->getHeader('Date')->getValue()) : null;
-	}
-
-	/**
-	 * Gets or creates the unique Message ID.
-	 * Requires Return-Path to be set.
-	 *
-	 * @return string|null
-	 */
-	public function getMessageId(): ?string
-	{
-		if (is_null($this->messageId) && $returnPath = $this->getReturnPath())
-		{
-			// Use a unique ID with the same domain as the Return-Path email
-			$this->messageId = '<' . uniqid('', true) . strstr($returnPath->getEmail(), '@'). '>';
-		}
-
-		return $this->messageId;
-	}
-
-	/**
-	 * Tracks boundary keys so they can be reused.
-	 *
-	 * @return string
-	 */
-	public function getBoundary(string $name): string
-	{
-		if (! isset($this->boundaries[$name]))
-		{
-			$this->boundaries[$name] = uniqid($name . '_', true);
-		}
-
-		return $this->boundaries[$name];
-	}
-
-	//--------------------------------------------------------------------
-	// Attachments
-	//--------------------------------------------------------------------
-
-	/**
-	 * Adds an Attachment.
-	 *
-	 * @param Attachment $attachment
-	 *
-	 * @return $this
-	 */
-	public function attach(Attachment $attachment): self
-	{
-		$this->attachments[] = $attachment;
-
-		return $this;
-	}
-
-	/**
-	 * Returns all or filtered Attachments.
-	 *
-	 * @param bool|null $contentFilter (Optional) Whether to include/exclude attachments with Content ID
-	 *
-	 * @return Attachment[]
-	 */
-	public function getAttachments(bool $contentFilter = null): array
-	{
-		if (is_null($contentFilter))
-		{
-			return $this->attachments;
-		}
-
-		$attachments = [];
-		foreach ($this->attachments as $attachment)
-		{
-			if ($contentFilter && $attachment->hasContentId())
-			{
-				$attachments[] = $attachment;
-			}
-			if (! $contentFilter && ! $attachment->hasContentId())
-			{
-				$attachments[] = $attachment;
-			}
-		}
-
-		return $attachments;
-	}
-
-	/**
-	 * Removes and returns all Attachments.
-	 *
-	 * @return Attachment[]
-	 */
-	public function detach(): array
-	{
-		$attachments = $this->getAttachments();
-
-		$this->attachments = [];
-
-		return $attachments;
-	}
-
-	//--------------------------------------------------------------------
-	// Backwards Compatibility
-	//--------------------------------------------------------------------
-
-	/**
-	 * @param string $body
-	 *
-	 * @return $this
-	 */
-	public function setMessage($body): self
-	{
-		return $this->body($body);
-	}
-
-	/**
-	 * Magic method to allow CI3-style methods (like "setReplyTo()") to
-	 * forward to their equivalent setters.
-	 *
-	 * @param string $name
-	 * @param array $arguments
-	 *
-	 * @return mixed
-	 *
-	 * @throws BadMethodCallException
-	 */
-	public function __call(string $name, array $arguments)
-	{
-		if (strpos($name, 'set') === 0 && method_exists($this, $method = lcfirst(substr($name, 3))))
-		{
-			return $this->$method(...$arguments);
-		}
-
-		throw new BadMethodCallException("Method {$name} does not exist");
-	}
+    /**
+     * Array of priorities and their encoded value.
+     */
+    private const PRIORITIES = [
+        1 => '1 (Highest)',
+        2 => '2 (High)',
+        3 => '3 (Normal)',
+        4 => '4 (Low)',
+        5 => '5 (Lowest)',
+    ];
+
+    /**
+     * Array of Headers to collapse into a CSV.
+     */
+    private const CSV_HEADERS = ['To', 'Cc', 'Bcc'];
+
+    /**
+     * Attachments to this email
+     *
+     * @var Attachment[]
+     */
+    protected $attachements = [];
+
+    /**
+     * This email's unique Message ID.
+     *
+     * @var string|null
+     */
+    private $messageId;
+
+    /**
+     * Boundaries for header & body divisions.
+     *
+     * @var array<string,string>
+     */
+    private $boundaries = [];
+
+    /**
+     * Stores any initial values.
+     */
+    public function __construct(array $data = [])
+    {
+        $this->set($data);
+    }
+
+    /**
+     * Resets $messageId for clones to ensure each is unique.
+     */
+    public function __clone()
+    {
+        unset($this->messageId);
+    }
+
+    //--------------------------------------------------------------------
+    // Class Operations
+    //--------------------------------------------------------------------
+
+    /**
+     * Bulk stores values by matching input keys to their setter method.
+     *
+     * @return $this
+     */
+    public function set(array $data, bool $overwrite = true): self
+    {
+        // Check for matching keys
+        foreach ([
+            'body',
+            'subject',
+            'from',
+            'to',
+            'cc',
+            'bcc',
+            'replyTo',
+            'returnPath',
+            'priority',
+            'date',
+        ] as $setter) {
+            $getter = 'get' . ucfirst($setter);
+
+            if (array_key_exists($setter, $data)) {
+                if ($overwrite || null === $this->{$getter}()) {
+                    $this->{$method}($data[$method]);
+                }
+            }
+        }
+
+        return $this;
+    }
+
+    /**
+     * Compiles headers into a spool-ready string.
+     *
+     * @param string        $newline Character(s) to use when combining the sequence
+     * @param string[]|null $exclude An array of header names to exclude
+     * @param string[]|null $include An array of header names to include
+     */
+    public function getHeaderString(string $newline = "\r\n", ?array $exclude = null, ?array $include = null): string
+    {
+        $string = '';
+
+        // Use $headers directly instead of headers() so as not to trigger populateHeaders()
+        foreach ($this->headers as $name => $value) {
+            // Check exclusion
+            if (isset($exclude) && in_array($name, $exclude, true)) {
+                continue;
+            }
+            // Check includion
+            if (isset($include) && ! in_array($name, $include, true)) {
+                continue;
+            }
+
+            // Check for a collapsible
+            if (in_array($name, self::CSV_HEADERS, true) && is_array($value)) {
+                $string .= implode(',', array_map('__toString', $value));
+            } elseif (is_array($value)) {
+                foreach ($value as $header) {
+                    $string .= $header . $this->newline;
+                }
+            } else {
+                $string .= $value . $this->newline; // Trailing newline is intentional
+            }
+        }
+    }
+
+    //--------------------------------------------------------------------
+    // Setters
+    //--------------------------------------------------------------------
+
+    /**
+     * Intercepts calls to Message::setBody() to enforce formatting.
+     *
+     * @param string $body
+     *
+     * @return $this
+     */
+    public function setBody($body): self
+    {
+        return $this->body($body);
+    }
+
+    /**
+     * @return $this
+     */
+    public function body(string $body)
+    {
+        return parent::setBody(rtrim(str_replace("\r", '', $body)));
+    }
+
+    /**
+     * @return $this
+     */
+    public function subject(string $subject)
+    {
+        return $this->setHeader('Subject', $subject);
+    }
+
+    /**
+     * @return $this
+     */
+    public function from(string $address)
+    {
+        return $this->setHeader('From', Address::create($address));
+    }
+
+    /**
+     * @param Address|string ...$addresses
+     *
+     * @return $this
+     */
+    public function to(...$addresses)
+    {
+        return $this->setHeader('To', Address::createArray($addresses));
+    }
+
+    /**
+     * @param Address|string ...$addresses
+     *
+     * @return $this
+     */
+    public function cc(...$addresses)
+    {
+        return $this->setHeader('Cc', Address::createArray($addresses));
+    }
+
+    /**
+     * @param Address|string ...$addresses
+     *
+     * @return $this
+     */
+    public function bcc(...$addresses)
+    {
+        return $this->setHeader('Bcc', Address::createArray($addresses));
+    }
+
+    /**
+     * @return $this
+     */
+    public function replyTo(string $address)
+    {
+        return $this->setHeader('From', Address::create($address));
+    }
+
+    /**
+     * Return-Path must be only an email enclosed in angle brackets, e.g. "<admin@codeigniter.com>"
+     *
+     * @return $this
+     */
+    public function returnPath(string $address)
+    {
+        // Force Address to use angle braces by giving an empty display name
+        $email = Address::split($address)['email'];
+
+        return $this->setHeader('Return-Path', new Address($email, ''));
+    }
+
+    /**
+     * Sets the priority, where 1 is the highest and 5 is the lowest.
+     *
+     * @return $this
+     */
+    public function priority(int $priority)
+    {
+        $priority = max($priority, 1);
+        $priority = min($priority, 5);
+
+        return $this->setHeader('X-Priority', self::PRIORITIES[$priority]);
+    }
+
+    /**
+     * @return $this
+     */
+    public function date(DateTimeInterface $date)
+    {
+        return $this->setHeader('Date', (string) Time::createFromInstance($date));
+    }
+
+    //--------------------------------------------------------------------
+    // Getters
+    //--------------------------------------------------------------------
+
+    public function getSubject(): ?string
+    {
+        return $this->hasHeader('Subject') ? $this->getHeader('Subject')->getValue() : null;
+    }
+
+    public function getFrom(): ?Address
+    {
+        return $this->hasHeader('From') ? Address::create($this->getHeader('From')->getValue()) : null;
+    }
+
+    /**
+     * @return Address[]|null
+     */
+    public function getTo(): ?array
+    {
+        return $this->hasHeader('To') ? Address::createArray($this->getHeader('To')->getValue()) : null;
+    }
+
+    /**
+     * @return Address[]|null
+     */
+    public function getCc(): ?array
+    {
+        return $this->hasHeader('Cc') ? Address::createArray($this->getHeader('Cc')->getValue()) : null;
+    }
+
+    /**
+     * @return Address[]|null
+     */
+    public function getBcc(): ?array
+    {
+        return $this->hasHeader('Bcc') ? Address::createArray($this->getHeader('Bcc')->getValue()) : null;
+    }
+
+    public function getReplyTo(): ?Address
+    {
+        return $this->hasHeader('Reply-To') ? Address::create($this->getHeader('Reply-To')->getValue()) : null;
+    }
+
+    public function getReturnPath(): ?Address
+    {
+        if (! $this->hasHeader('Return-Path')) {
+            return null;
+        }
+
+        // Get just the email portion of the stored address
+        $address = $this->getHeader('Return-Path')->getValue();
+        $email   = Address::split($address)['email'];
+
+        // Force Address to use angle braces by giving an empty display name
+        return new Address($email, '');
+    }
+
+    /**
+     * Returns the priority as an integer parsed from the header,
+     * where 1 is the highest and 5 is the lowest.
+     *
+     * @return int
+     */
+    public function getPriority(): ?int
+    {
+        if ($this->hasHeader('X-Priority')) {
+            return array_search($this->getHeader('X-Priority')->getValue(), self::PRIORITIES, true) ?: null;
+        }
+
+        return null;
+    }
+
+    public function getDate(): ?Time
+    {
+        return $this->hasHeader('Date') ? Time::parse($this->getHeader('Date')->getValue()) : null;
+    }
+
+    /**
+     * Gets or creates the unique Message ID.
+     * Requires Return-Path to be set.
+     */
+    public function getMessageId(): ?string
+    {
+        if (null === $this->messageId && $returnPath = $this->getReturnPath()) {
+            // Use a unique ID with the same domain as the Return-Path email
+            $this->messageId = '<' . uniqid('', true) . strstr($returnPath->getEmail(), '@') . '>';
+        }
+
+        return $this->messageId;
+    }
+
+    /**
+     * Tracks boundary keys so they can be reused.
+     */
+    public function getBoundary(string $name): string
+    {
+        if (! isset($this->boundaries[$name])) {
+            $this->boundaries[$name] = uniqid($name . '_', true);
+        }
+
+        return $this->boundaries[$name];
+    }
+
+    //--------------------------------------------------------------------
+    // Attachments
+    //--------------------------------------------------------------------
+
+    /**
+     * Adds an Attachment.
+     *
+     * @return $this
+     */
+    public function attach(Attachment $attachment): self
+    {
+        $this->attachments[] = $attachment;
+
+        return $this;
+    }
+
+    /**
+     * Returns all or filtered Attachments.
+     *
+     * @param bool|null $contentFilter (Optional) Whether to include/exclude attachments with Content ID
+     *
+     * @return Attachment[]
+     */
+    public function getAttachments(?bool $contentFilter = null): array
+    {
+        if (null === $contentFilter) {
+            return $this->attachments;
+        }
+
+        $attachments = [];
+
+        foreach ($this->attachments as $attachment) {
+            if ($contentFilter && $attachment->hasContentId()) {
+                $attachments[] = $attachment;
+            }
+            if (! $contentFilter && ! $attachment->hasContentId()) {
+                $attachments[] = $attachment;
+            }
+        }
+
+        return $attachments;
+    }
+
+    /**
+     * Removes and returns all Attachments.
+     *
+     * @return Attachment[]
+     */
+    public function detach(): array
+    {
+        $attachments = $this->getAttachments();
+
+        $this->attachments = [];
+
+        return $attachments;
+    }
+
+    //--------------------------------------------------------------------
+    // Backwards Compatibility
+    //--------------------------------------------------------------------
+
+    /**
+     * @param string $body
+     *
+     * @return $this
+     */
+    public function setMessage($body): self
+    {
+        return $this->body($body);
+    }
+
+    /**
+     * Magic method to allow CI3-style methods (like "setReplyTo()") to
+     * forward to their equivalent setters.
+     *
+     * @throws BadMethodCallException
+     *
+     * @return mixed
+     */
+    public function __call(string $name, array $arguments)
+    {
+        if (strpos($name, 'set') === 0 && method_exists($this, $method = lcfirst(substr($name, 3)))) {
+            return $this->{$method}(...$arguments);
+        }
+
+        throw new BadMethodCallException("Method {$name} does not exist");
+    }
 }
diff --git a/system/Mailer/Encode.php b/system/Mailer/Encode.php
index 03fe697d4725..51be89ea2d3f 100644
--- a/system/Mailer/Encode.php
+++ b/system/Mailer/Encode.php
@@ -1,12 +1,12 @@
 <?php
 
 /**
- * This file is part of the CodeIgniter 4 framework.
+ * This file is part of CodeIgniter 4 framework.
  *
  * (c) CodeIgniter Foundation <admin@codeigniter.com>
  *
- * For the full copyright and license information, please view the LICENSE
- * file that was distributed with this source code.
+ * For the full copyright and license information, please view
+ * the LICENSE file that was distributed with this source code.
  */
 
 namespace CodeIgniter\Mailer;
@@ -19,289 +19,249 @@
  * Handles the encoding of various portions of
  * an email into all their possible forms.
  *
- * @property-read string $charset
- * @property-read string $encoding
- * @property-read string $newline
- * @property-read string $crlf
+ * @property string $charset
+ * @property string $crlf
+ * @property string $encoding
+ * @property string $newline
  */
 final class Encode
 {
-	/**
-	 * Valid newline characters.
-	 */
-	private const NEWLINES = [
-		"\r\n",
-		"\r",
-		"\n",
-	];
-
-	/**
-	 * Valid mail encodings
-	 */
-	private const ENCODINGS = [
-		'7bit',
-		'8bit',
-	];
-
-	/**
-	 * Character sets valid for 7-bit encoding, excluding language suffix.
-	 */
-	private const CHARSETS = [
-		'us-ascii',
-		'iso-2022-',
-	];
-
-	/**
-	 * ASCII code numbers for "safe" characters that can always be used literally,
-	 * without encoding, as described in RFC 2049.
-	 *
-	 * @link http://www.ietf.org/rfc/rfc2049.txt
-	 */
-	private const ASCII_SAFE = [
-		// ' (  )   +   ,   -   .   /   :   =   ?
-		39, 40, 41, 43, 44, 45, 46, 47, 58, 61, 63,
-		// digits
-		48, 49, 50, 51, 52, 53, 54, 55, 56, 57,
-		// upper-case letters
-		65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90,
-		// lower-case letters
-		97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122,
-	];
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Character set.
-	 *
-	 * @var string
-	 */
-	private $charset;
-
-	/**
-	 * Mail encoding
-	 *
-	 * @var string
-	 */
-	private $encoding;
-
-	/**
-	 * Newline character sequence.
-	 *
-	 * @link http://www.ietf.org/rfc/rfc822.txt
-	 * @var string
-	 */
-	private $newline;
-
-	/**
-	 * CRLF character sequence
-	 *
-	 * @link http://www.ietf.org/rfc/rfc822.txt
-	 * @var string
-	 */
-	private $crlf;
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Validates and stores config values.
-	 *
-	 * @param Mailer $config
-	 */
-	public function __construct(Mailer $config)
-	{
-		// Make sure charset is the correct case
-		$this->charset = strtoupper($config->charset);
-
-		// Validate newline values
-		$this->newline = in_array($config->newline, self::NEWLINES, true) ? $config->newline : "\r\n";
-		$this->crlf    = in_array($config->crlf, ["\r\n", "\r", "\n"], true) ? $config->crlf : "\r\n";
-
-		// Check for charsets that need 7bit
-		foreach (self::CHARSETS as $charset)
-		{
-			if (strpos($this->charset, $charset) === 0)
-			{
-				$this->encoding = '7bit';
-				break;
-			}
-		}
-
-		// Validate encoding
-		$this->encoding = in_array($config->encoding, self::ENCODINGS, true) ? $config->encoding : '8bit';
-	}
-
-	/**
-	 * Allows access to the stored, validated properties.
-	 *
-	 * @param string $name
-	 *
-	 * @return string
-	 */
-	public function __get(string $name): string
-	{
-		return $this->$name;
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Encodes the name portion of an Address, applying Q encoding
-	 * if necessary, or escaping unsafe characters otherwise
-	 *
-	 * @param Address $address
-	 *
-	 * @return Address
-	 */
-	public function address(Address $address): Address
-	{
-		// The email has already been verified so encoding only applies to the display name
-		if (empty($address->getName()))
-		{
-			return $address;
-		}
-
-		$name = $address->getName();
-
-		// Use Q encoding if there are any characters that require it
-		if (preg_match('/[\200-\377]/', $name))
-		{
-			$name = $this->Q($name);
-		}
-		// Otherwise, escape non-printing characters, slashes, and double quotes
-		else
-		{
-			$name = addcslashes($name, "\0..\37\177'\"\\");
-		}
-
-		return new Address($address->getEmail(), $name);
-	}
-
-	/**
-	 * Performs "Q Encoding" on a string for use in email headers.
-	 * This is mostly straight from CodeIgniter 3.
-	 *
-	 * @see https://www.freesoft.org/CIE/RFC/1522/6.htm
-	 *
-	 * @param string $string
-	 *
-	 * @return string
-	 */
-	public function Q(string $string): string
-	{
-		$string = str_replace(["\r", "\n"], '', $string);
-		$output = '=?' . $this->charset . '?Q?';
-		$chars  = $this->charset === 'UTF-8' ? mb_strlen($string, 'UTF-8') : mb_strlen($string, '8bit');
-		$length = mb_strlen($output, '8bit');
-
-		for ($i = 0; $i < $chars; $i++)
-		{
-			$chr = ($this->charset === 'UTF-8' && extension_loaded('iconv'))
-				? '=' . implode('=', str_split(strtoupper(bin2hex(iconv_substr($string, $i, 1, $this->charset))), 2))
-				: '=' . strtoupper(bin2hex($string[$i]));
-
-			$chrlen = mb_strlen($chr, '8bit');
-
-			// RFC 2045 sets a limit of 76 characters per line, but leave space for ?= at the end of each line
-			if ($length + $chrlen > 74)
-			{
-				$output .= '?=' . $this->crlf // EOL
-					. ' =?' . $this->charset . '?Q?' . $chr; // New line
-
-				$length = 6 + mb_strlen($this->charset, '8bit') + $chrlen; // Reset the length for the new line
-			}
-			else
-			{
-				$output .= $chr;
-				$length += $chrlen;
-			}
-		}
-
-		// End the header
-		return $output . '?=';
-	}
-	/**
-	 * Prepares a string for Quoted-Printable Content-Transfer-Encoding
-	 * Refer to RFC 2045 http://www.ietf.org/rfc/rfc2045.txt
-	 *
-	 * @param string $str
-	 *
-	 * @return string
-	 */
-	public function quotedPrintable(string $str): string
-	{
-		// RFC 2045 specifies CRLF as "\r\n".
-		// However, many developers choose to override that and violate
-		// the RFC rules due to (apparently) a bug in MS Exchange,
-		// which only works with "\n".
-		if ($this->crlf === "\r\n")
-		{
-			return quoted_printable_encode($str);
-		}
-
-		// Reduce multiple spaces & remove nulls
-		$str = preg_replace(['| +|', '/\x00+/'], [' ', ''], $str);
-
-		// Standardize newlines
-		if (strpos($str, "\r") !== false)
-		{
-			$str = str_replace(["\r\n", "\r"], "\n", $str);
-		}
-
-		$escape = '=';
-		$output = '';
-
-		foreach (explode("\n", $str) as $line)
-		{
-			$length = mb_strlen($line);
-			$temp   = '';
-
-			// Loop through each character in the line to add soft-wrap
-			// characters at the end of a line " =\r\n" and add the newly
-			// processed line(s) to the output (see comment on $crlf class property)
-			for ($i = 0; $i < $length; $i ++)
-			{
-				// Grab the next character
-				$char  = $line[$i];
-				$ascii = ord($char);
-
-				// Convert spaces and tabs but only if it's the end of the line
-				if ($ascii === 32 || $ascii === 9)
-				{
-					if ($i === ($length - 1))
-					{
-						$char = $escape . sprintf('%02s', dechex($ascii));
-					}
-				}
-				// DO NOT move this below the self::ASCII_SAFE line!
-				//
-				// = (equals) signs are allowed by RFC2049, but must be encoded
-				// as they are the encoding delimiter!
-				elseif ($ascii === 61)
-				{
-					$char = $escape . strtoupper(sprintf('%02s', dechex($ascii)));  // =3D
-				}
-				elseif (! in_array($ascii, self::ASCII_SAFE, true))
-				{
-					$char = $escape . strtoupper(sprintf('%02s', dechex($ascii)));
-				}
-
-				// If we're at the character limit, add the line to the output,
-				// reset our temp variable, and keep on chuggin'
-				if ((mb_strlen($temp) + mb_strlen($char)) >= 76)
-				{
-					$output .= $temp . $escape . $this->crlf;
-					$temp    = '';
-				}
-
-				// Add the character to our temporary line
-				$temp .= $char;
-			}
-
-			// Add our completed line to the output
-			$output .= $temp . $this->crlf;
-		}
-
-		// get rid of extra CRLF tacked onto the end
-		return mb_substr($output, 0, mb_strlen($this->crlf) * -1);
-	}
+    /**
+     * Valid newline characters.
+     */
+    private const NEWLINES = [
+        "\r\n",
+        "\r",
+        "\n",
+    ];
+
+    /**
+     * Valid mail encodings
+     */
+    private const ENCODINGS = [
+        '7bit',
+        '8bit',
+    ];
+
+    /**
+     * Character sets valid for 7-bit encoding, excluding language suffix.
+     */
+    private const CHARSETS = [
+        'us-ascii',
+        'iso-2022-',
+    ];
+
+    /**
+     * ASCII code numbers for "safe" characters that can always be used literally,
+     * without encoding, as described in RFC 2049.
+     *
+     * @see http://www.ietf.org/rfc/rfc2049.txt
+     */
+    private const ASCII_SAFE = [
+        // ' (  )   +   ,   -   .   /   :   =   ?
+        39, 40, 41, 43, 44, 45, 46, 47, 58, 61, 63,
+        // digits
+        48, 49, 50, 51, 52, 53, 54, 55, 56, 57,
+        // upper-case letters
+        65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90,
+        // lower-case letters
+        97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122,
+    ];
+
+    /**
+     * Character set.
+     *
+     * @var string
+     */
+    private $charset;
+
+    /**
+     * Mail encoding
+     *
+     * @var string
+     */
+    private $encoding;
+
+    /**
+     * Newline character sequence.
+     *
+     * @see http://www.ietf.org/rfc/rfc822.txt
+     *
+     * @var string
+     */
+    private $newline;
+
+    /**
+     * CRLF character sequence
+     *
+     * @see http://www.ietf.org/rfc/rfc822.txt
+     *
+     * @var string
+     */
+    private $crlf;
+
+    /**
+     * Validates and stores config values.
+     */
+    public function __construct(Mailer $config)
+    {
+        // Make sure charset is the correct case
+        $this->charset = strtoupper($config->charset);
+
+        // Validate newline values
+        $this->newline = in_array($config->newline, self::NEWLINES, true) ? $config->newline : "\r\n";
+        $this->crlf    = in_array($config->crlf, ["\r\n", "\r", "\n"], true) ? $config->crlf : "\r\n";
+
+        // Check for charsets that need 7bit
+        foreach (self::CHARSETS as $charset) {
+            if (strpos($this->charset, $charset) === 0) {
+                $this->encoding = '7bit';
+                break;
+            }
+        }
+
+        // Validate encoding
+        $this->encoding = in_array($config->encoding, self::ENCODINGS, true) ? $config->encoding : '8bit';
+    }
+
+    /**
+     * Allows access to the stored, validated properties.
+     */
+    public function __get(string $name): string
+    {
+        return $this->{$name};
+    }
+
+    /**
+     * Encodes the name portion of an Address, applying Q encoding
+     * if necessary, or escaping unsafe characters otherwise
+     */
+    public function address(Address $address): Address
+    {
+        // The email has already been verified so encoding only applies to the display name
+        if (empty($address->getName())) {
+            return $address;
+        }
+
+        $name = $address->getName();
+
+        // Use Q encoding if there are any characters that require it
+        if (preg_match('/[\200-\377]/', $name)) {
+            $name = $this->Q($name);
+        }
+        // Otherwise, escape non-printing characters, slashes, and double quotes
+        else {
+            $name = addcslashes($name, "\0..\37\177'\"\\");
+        }
+
+        return new Address($address->getEmail(), $name);
+    }
+
+    /**
+     * Performs "Q Encoding" on a string for use in email headers.
+     * This is mostly straight from CodeIgniter 3.
+     *
+     * @see https://www.freesoft.org/CIE/RFC/1522/6.htm
+     */
+    public function Q(string $string): string
+    {
+        $string = str_replace(["\r", "\n"], '', $string);
+        $output = '=?' . $this->charset . '?Q?';
+        $chars  = $this->charset === 'UTF-8' ? mb_strlen($string, 'UTF-8') : mb_strlen($string, '8bit');
+        $length = mb_strlen($output, '8bit');
+
+        for ($i = 0; $i < $chars; $i++) {
+            $chr = ($this->charset === 'UTF-8' && extension_loaded('iconv'))
+                ? '=' . implode('=', str_split(strtoupper(bin2hex(iconv_substr($string, $i, 1, $this->charset))), 2))
+                : '=' . strtoupper(bin2hex($string[$i]));
+
+            $chrlen = mb_strlen($chr, '8bit');
+
+            // RFC 2045 sets a limit of 76 characters per line, but leave space for ?= at the end of each line
+            if ($length + $chrlen > 74) {
+                $output .= '?=' . $this->crlf // EOL
+                    . ' =?' . $this->charset . '?Q?' . $chr; // New line
+
+                $length = 6 + mb_strlen($this->charset, '8bit') + $chrlen; // Reset the length for the new line
+            } else {
+                $output .= $chr;
+                $length += $chrlen;
+            }
+        }
+
+        // End the header
+        return $output . '?=';
+    }
+
+    /**
+     * Prepares a string for Quoted-Printable Content-Transfer-Encoding
+     * Refer to RFC 2045 http://www.ietf.org/rfc/rfc2045.txt
+     */
+    public function quotedPrintable(string $str): string
+    {
+        // RFC 2045 specifies CRLF as "\r\n".
+        // However, many developers choose to override that and violate
+        // the RFC rules due to (apparently) a bug in MS Exchange,
+        // which only works with "\n".
+        if ($this->crlf === "\r\n") {
+            return quoted_printable_encode($str);
+        }
+
+        // Reduce multiple spaces & remove nulls
+        $str = preg_replace(['| +|', '/\x00+/'], [' ', ''], $str);
+
+        // Standardize newlines
+        if (strpos($str, "\r") !== false) {
+            $str = str_replace(["\r\n", "\r"], "\n", $str);
+        }
+
+        $escape = '=';
+        $output = '';
+
+        foreach (explode("\n", $str) as $line) {
+            $length = mb_strlen($line);
+            $temp   = '';
+
+            // Loop through each character in the line to add soft-wrap
+            // characters at the end of a line " =\r\n" and add the newly
+            // processed line(s) to the output (see comment on $crlf class property)
+            for ($i = 0; $i < $length; $i++) {
+                // Grab the next character
+                $char  = $line[$i];
+                $ascii = ord($char);
+
+                // Convert spaces and tabs but only if it's the end of the line
+                if ($ascii === 32 || $ascii === 9) {
+                    if ($i === ($length - 1)) {
+                        $char = $escape . sprintf('%02s', dechex($ascii));
+                    }
+                }
+                // DO NOT move this below the self::ASCII_SAFE line!
+                //
+                // = (equals) signs are allowed by RFC2049, but must be encoded
+                // as they are the encoding delimiter!
+                elseif ($ascii === 61) {
+                    $char = $escape . strtoupper(sprintf('%02s', dechex($ascii)));  // =3D
+                } elseif (! in_array($ascii, self::ASCII_SAFE, true)) {
+                    $char = $escape . strtoupper(sprintf('%02s', dechex($ascii)));
+                }
+
+                // If we're at the character limit, add the line to the output,
+                // reset our temp variable, and keep on chuggin'
+                if ((mb_strlen($temp) + mb_strlen($char)) >= 76) {
+                    $output .= $temp . $escape . $this->crlf;
+                    $temp = '';
+                }
+
+                // Add the character to our temporary line
+                $temp .= $char;
+            }
+
+            // Add our completed line to the output
+            $output .= $temp . $this->crlf;
+        }
+
+        // get rid of extra CRLF tacked onto the end
+        return mb_substr($output, 0, mb_strlen($this->crlf) * -1);
+    }
 }
diff --git a/system/Mailer/Exceptions/MailerException.php b/system/Mailer/Exceptions/MailerException.php
index 338595890759..703b6d14eea4 100644
--- a/system/Mailer/Exceptions/MailerException.php
+++ b/system/Mailer/Exceptions/MailerException.php
@@ -1,12 +1,12 @@
 <?php
 
 /**
- * This file is part of the CodeIgniter 4 framework.
+ * This file is part of CodeIgniter 4 framework.
  *
  * (c) CodeIgniter Foundation <admin@codeigniter.com>
  *
- * For the full copyright and license information, please view the LICENSE
- * file that was distributed with this source code.
+ * For the full copyright and license information, please view
+ * the LICENSE file that was distributed with this source code.
  */
 
 namespace CodeIgniter\Mailer\Exceptions;
@@ -15,125 +15,121 @@
 
 class MailerException extends FrameworkException
 {
-	/**
-	 * Thrown when specified handler was not found.
-	 *
-	 * @return static
-	 */
-	public static function forHandlerNotFound()
-	{
-		return new static(lang('Mailer.handlerNotFound'));
-	}
-
-	/**
-	 * Thrown when specified handler is not supported.
-	 *
-	 * @param string $class
-	 *
-	 * @return static
-	 */
-	public static function forHandlerNotSupported(string $class)
-	{
-		return new static(lang('Mailer.handlerNotSupported', [$class]));
-	}
-
-	/**
-	 * Thrown when an email address fails validation
-	 *
-	 * @param string|null $value
-	 *
-	 * @return static
-	 */
-	public static function forInvalidAddress(string $value = null)
-	{
-		return new static(lang('Mailer.invalidAddress', [$value]));
-	}
-
-	/**
-	 * Thrown when an Email is missing the "From" header
-	 *
-	 * @return static
-	 */
-	public static function forNoFrom()
-	{
-		return new static(lang('Mailer.noFrom'));
-	}
-
-	/**
-	 * Thrown when an Email has no "To", "Cc", and "Bcc" headers
-	 *
-	 * @return static
-	 */
-	public static function forNoRecipients()
-	{
-		return new static(lang('Mailer.noRecipients'));
-	}
-
-/*
-	public static function forAttachmentMissing(string $file = null)
-	{
-		return new static(lang('Mailer.attachmentMissing', [$file]));
-	}
-
-	public static function forAttachmentUnreadable(string $file = null)
-	{
-		return new static(lang('Mailer.attachmentUnreadable', [$file]));
-	}
-
-	public static function forMustBeArray()
-	{
-		return new static(lang('Mailer.mustBeArray', []));
-	}
-
-
-	public static function forInvalidProtocol(string $value = null)
-	{
-		return new static(lang('Mailer.invalidProtocolRequested', [$value]));
-	}
-
-	public static function forSendFailure(string $protocol = '?')
-	{
-		return new static(lang('Mailer.SendFailure', [$protocol]));
-	}
-
-	public static function forNosocket(string $status = '?')
-	{
-		return new static(lang('Mailer.exitStatus', [$status]) . lang('Mailer.nosocket', []));
-	}
-
-	public static function forNoHostname()
-	{
-		return new static(lang('Mailer.noHostname', []));
-	}
-
-	public static function forSMTPError(string $reply = '?')
-	{
-		return new static(lang('Mailer.SMTPError', [$reply]));
-	}
-
-	public static function forNoSMTPAuth()
-	{
-		return new static(lang('Mailer.noSMTPAuth', []));
-	}
-
-	public static function forFailedSMTPLogin(string $reply = '?')
-	{
-		return new static(lang('Mailer.failedSMTPLogin', [$reply]));
-	}
-
-	public static function forSMTPAuthUsername(string $reply = '?')
-	{
-		return new static(lang('Mailer.SMTPAuthUsername', [$reply]));
-	}
-
-	public static function forSMTPAuthPassword(string $reply = '?')
-	{
-		return new static(lang('Mailer.SMTPAuthPassword', [$reply]));
-	}
-
-	public static function forSMTPDataFailure(string $data = '?')
-	{
-		return new static(lang('Mailer.SMTPDataFailure', [$data]));
-	}
-*/
+    /**
+     * Thrown when specified handler was not found.
+     *
+     * @return static
+     */
+    public static function forHandlerNotFound()
+    {
+        return new static(lang('Mailer.handlerNotFound'));
+    }
+
+    /**
+     * Thrown when specified handler is not supported.
+     *
+     * @return static
+     */
+    public static function forHandlerNotSupported(string $class)
+    {
+        return new static(lang('Mailer.handlerNotSupported', [$class]));
+    }
+
+    /**
+     * Thrown when an email address fails validation
+     *
+     * @return static
+     */
+    public static function forInvalidAddress(?string $value = null)
+    {
+        return new static(lang('Mailer.invalidAddress', [$value]));
+    }
+
+    /**
+     * Thrown when an Email is missing the "From" header
+     *
+     * @return static
+     */
+    public static function forNoFrom()
+    {
+        return new static(lang('Mailer.noFrom'));
+    }
+
+    /**
+     * Thrown when an Email has no "To", "Cc", and "Bcc" headers
+     *
+     * @return static
+     */
+    public static function forNoRecipients()
+    {
+        return new static(lang('Mailer.noRecipients'));
+    }
+
+    /*
+        public static function forAttachmentMissing(string $file = null)
+        {
+            return new static(lang('Mailer.attachmentMissing', [$file]));
+        }
+
+        public static function forAttachmentUnreadable(string $file = null)
+        {
+            return new static(lang('Mailer.attachmentUnreadable', [$file]));
+        }
+
+        public static function forMustBeArray()
+        {
+            return new static(lang('Mailer.mustBeArray', []));
+        }
+
+
+        public static function forInvalidProtocol(string $value = null)
+        {
+            return new static(lang('Mailer.invalidProtocolRequested', [$value]));
+        }
+
+        public static function forSendFailure(string $protocol = '?')
+        {
+            return new static(lang('Mailer.SendFailure', [$protocol]));
+        }
+
+        public static function forNosocket(string $status = '?')
+        {
+            return new static(lang('Mailer.exitStatus', [$status]) . lang('Mailer.nosocket', []));
+        }
+
+        public static function forNoHostname()
+        {
+            return new static(lang('Mailer.noHostname', []));
+        }
+
+        public static function forSMTPError(string $reply = '?')
+        {
+            return new static(lang('Mailer.SMTPError', [$reply]));
+        }
+
+        public static function forNoSMTPAuth()
+        {
+            return new static(lang('Mailer.noSMTPAuth', []));
+        }
+
+        public static function forFailedSMTPLogin(string $reply = '?')
+        {
+            return new static(lang('Mailer.failedSMTPLogin', [$reply]));
+        }
+
+        public static function forSMTPAuthUsername(string $reply = '?')
+        {
+            return new static(lang('Mailer.SMTPAuthUsername', [$reply]));
+        }
+
+        public static function forSMTPAuthPassword(string $reply = '?')
+        {
+            return new static(lang('Mailer.SMTPAuthPassword', [$reply]));
+        }
+
+        public static function forSMTPDataFailure(string $data = '?')
+        {
+            return new static(lang('Mailer.SMTPDataFailure', [$data]));
+        }
+    */
 }
diff --git a/system/Mailer/Format.php b/system/Mailer/Format.php
index 2d16dd02bd3b..444c952ad3c2 100644
--- a/system/Mailer/Format.php
+++ b/system/Mailer/Format.php
@@ -1,12 +1,12 @@
 <?php
 
 /**
- * This file is part of the CodeIgniter 4 framework.
+ * This file is part of CodeIgniter 4 framework.
  *
  * (c) CodeIgniter Foundation <admin@codeigniter.com>
  *
- * For the full copyright and license information, please view the LICENSE
- * file that was distributed with this source code.
+ * For the full copyright and license information, please view
+ * the LICENSE file that was distributed with this source code.
  */
 
 namespace CodeIgniter\Mailer;
diff --git a/system/Mailer/Handlers/BaseHandler.php b/system/Mailer/Handlers/BaseHandler.php
index 82b090ac0b87..9fa2aafe0420 100644
--- a/system/Mailer/Handlers/BaseHandler.php
+++ b/system/Mailer/Handlers/BaseHandler.php
@@ -1,12 +1,12 @@
 <?php
 
 /**
- * This file is part of the CodeIgniter 4 framework.
+ * This file is part of CodeIgniter 4 framework.
  *
  * (c) CodeIgniter Foundation <admin@codeigniter.com>
  *
- * For the full copyright and license information, please view the LICENSE
- * file that was distributed with this source code.
+ * For the full copyright and license information, please view
+ * the LICENSE file that was distributed with this source code.
  */
 
 namespace CodeIgniter\Mailer\Handlers;
@@ -24,380 +24,341 @@
  */
 abstract class BaseHandler implements MailerInterface
 {
-	/**
-	 * Protocol for this handler.
-	 * Set by child classes.
-	 *
-	 * @var string
-	 */
-	protected $protocol;
-
-	/**
-	 * The Mailer config.
-	 *
-	 * @var Mailer|null
-	 */
-	protected $config;
-
-	/**
-	 * The config-specific Encode instance.
-	 *
-	 * @var Encode
-	 */
-	protected $encode;
-
-	/**
-	 * The config-specific Format instance.
-	 *
-	 * @var Format
-	 */
-	protected $format;
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Whether this handler is supported on this system.
-	 *
-	 * @return boolean
-	 */
-	abstract public function isSupported(): bool;
-
-	/**
-	 * Spools an Email to the server.
-	 *
-	 * @param Email $email
-	 *
-	 * @return boolean
-	 */
-	abstract protected function spool(Email $email);
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Stores the Mailer config and preps encoding and formatting.
-	 *
-	 * @param Mailer $config
-	 */
-	public function __construct(Mailer $config)
-	{
-		helper(['text']);
-
-		$this->config = clone $config;
-		$this->encode = new Encode($this->config);
-		$this->format = new Format($this->config);
-
-		// Enforce a few config validations
-		$this->config->format    = in_array($this->config->format, ['html', 'text']) ? $this->config->format : 'text';
-		$this->config->wordWrap  = is_bool($this->config->wordWrap) ? $this->config->wordWrap : true;
-		$this->config->wrapChars = is_int($this->config->wrapChars) ? $this->config->wrapChars : 76;
-	}
-
-	/**
-	 * Gets the Mailer config.
-	 *
-	 * @return Mailer
-	 */
-	public function getConfig(Mailer $config): Mailer
-	{
-		return $this->config;
-	}
-
-	/**
-	 * Gets the protocol.
-	 *
-	 * @return string
-	 */
-	public function getProtocol(): string
-	{
-		return $this->protocol;
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Sends an Email.
-	 *
-	 * @param Email $email
-	 */
-	public function send(Email $email)
-	{
-		$this->buildHeaders($email);
-		$this->buildMessage($email);
-
-		// Check for a batch request
-		if ($this->config->batchMode)
-		{
-			// Temporarily disable batch mode to prevent recursion
-			$this->config->batchMode = false;
-			$bccs = $email->getBcc();
-
-			try
-			{
-				foreach (array_chunk($bccs, $this->config->batchSize) as $bcc)
-				{
-					$batch = clone $email;
-					$batch->bcc($bcc);
-
-					$this->send($batch);
-				}
-			}
-			// Restore batch mode
-			finally
-			{
-				$this->config->batchMode = true;
-			}
-
-			return;
-		}
-
-		$result = $this->spool($email);
-
-/* WIP
-		if ($result)
-		{
-			$this->setArchiveValues();
-
-			if ($autoClear)
-			{
-				$this->clear();
-			}
-
-			Events::trigger('email_sent', $email);
-		}
-*/
-		return $result;
-	}
-
-	/**
-	 * Builds the remaining Email headers (including config defaults)
-	 * and validates all required headers are present.
-	 *
-	 * @return Mailer
-	 *
-	 * @throws MailerException
-	 */
-	protected function buildHeaders(Email $email): self
-	{
-		// Apply any missing defaults from the config
-		$email->set($this->config->defaults, false);
-
-		// Must have a sender
-		if (is_null($email->getFrom()))
-		{
-			throw MailerException::forNoFrom();
-		}
-		// Must have at least one recipient
-		if (empty($email->getTo()) && empty($email->getCc()) && empty($email->getBcc()))
-		{
-			throw MailerException::forNoRecipients();
-		}
-
-		// If no "reply to" header was set then use the From value
-		if (is_null($email->getReplyTo()) && $from = $email->getFrom())
-		{
-			$email->setReplyTo($from);
-		}
-		// If no priority header was set then use "normal"
-		if (is_null($email->getPriority()))
-		{
-			$email->setPriority(3);
-		}
-
-		// Set transport headers directly
-		$email->setHeader('User-Agent', $this->config->userAgent);
-		$email->setHeader('X-Mailer', $this->config->userAgent);
-		$email->setHeader('X-Sender', $email->getFrom()->getEmail());
-		$email->setHeader('Message-ID', $email->getMessageID());
-		$email->setHeader('Mime-Version', '1.0');
-
-		// Content headers take a bit more calculating
-		$this->buildContentHeaders($email);
-
-		return $this;
-	}
-
-	/**
-	 * Caculates and sets the Headers for Content-Type and Content-Transfer-Encoding.
-	 *
-	 * @param Email
-	 *
-	 * @return $this
-	 */
-	protected function buildContentHeaders(Email $email): self
-	{
-		// If there are no attachments this is much easier
-		if ($email->getAttachments() === [])
-		{
-			// text
-			if ($this->config->mailFormat == 'text')
-			{
-				$email->setHeader('Content-Type', 'text/plain; charset=' . $this->encode->charset);
-				$email->setHeader('Content-Transfer-Encoding', 'text/plain; charset=' . $this->encode->charset);
-
-				return $this;
-			}
-
-			/**
-			 * Version 3 edition supported forced multipart messages for html format despite
-			 * it not being in the configuration or documentation. Should this feature need
-			 * to be added back then this is the appropriate place.
-			 */
-
-			// html
-			$email->setHeader('Content-Type', 'text/html; charset=' . $this->encode->charset);
-			$email->setHeader('Content-Transfer-Encoding', 'quoted-printable');
-
-			return $this;
-		}
-
-		// text + attachments
-		if ($this->config->mailFormat == 'text')
-		{
-			$email->setHeader('Content-Type', 'multipart/mixed; boundary=' . $email->getBoundary('B_ATC'));
-
-			return $this;
-		}
-
-		// html + attachments
-		if ($email->getAttachments(false))
-		{
-			$email->setHeader('Content-Type', 'multipart/mixed; boundary=' . $email->getBoundary('B_ATC'));
-		}
-		if ($email->getAttachments(true))
-		{
-			$email->setHeader('Content-Type', 'multipart/related; boundary=' . $email->getBoundary('B_REL'));
-		}
-	}
-
-	/**
-	 * Returns the string version of the Headers from the email.
-	 * Split out for handlers that need to skip the subject.
-	 *
-	 * @param Email
-	 *
-	 * @return string
-	 */
-	protected function getHeaderString(Email $email): string
-	{
-		return $email->getHeaderString($this->config->newline);
-	}
-
-	/**
-	 * Returns the string version of the message, including all headers and attachments.
-	 *
-	 * @param Email
-	 *
-	 * @return string
-	 */
-	protected function getMessageString(Email $email): string
-	{
-		$message = '';
-
-		// If there are no attachments this is much easier
-		if ($email->getAttachments() === [])
-		{
-			// text
-			if ($this->config->format == 'text')
-			{
-				$message .= $email->getHeaderString($this->config->newline, null, ['Content-Type', 'Content-Transfer-Encoding']);
-				$message .= $this->config->newline . $this->config->newline;
-				$message .= $this->config->wordWrap ? word_wrap($email->getBody()) : $email->getBody();
-
-				return $message;
-			}
-
-			// html
-			$message .= $email->getHeaderString($this->config->newline, null, ['Content-Type', 'Content-Transfer-Encoding']);
-			$message .= $this->config->newline . $this->config->newline;
-			$message .= $this->encode->quotedPrintable($email->getBody()) . $this->config->newline . $this->config->newline;
-
-			return $message;
-		}
-
-		// text + attachment
-		if ($this->config->format == 'text')
-		{
-			$message .= $email->getHeaderString($this->config->newline, null, ['Content-Type']);
-			$message .= $this->config->newline . $this->config->newline;
-
-			$message .= lang('Mailer.mimeMessage', [$this->config->newline])
-					. $this->config->newline . $this->config->newline
-					. '--' . $email->getBoundary('B_ATC') . $this->config->newline
-					. 'Content-Type: text/plain; charset=' . $this->encode->charset . $this->config->newline
-					. 'Content-Transfer-Encoding: ' . $this->encode->encoding . $this->config->newline
-					. $this->config->newline
-					. $email->getBody() . $this->config->newline . $this->config->newline;
-
-			$this->appendAttachments($body, $boundary);
-
-			return $message;
-		}
-
-		// html + attachments
-
-/* WIP
-		$alt_boundary  = uniqid('B_ALT_', true);
-		$last_boundary = null;
-
-		if ($this->attachmentsHaveMultipart('mixed'))
-		{
-			$atc_boundary  = uniqid('B_ATC_', true);
-			$hdr          .= 'Content-Type: multipart/mixed; boundary="' . $atc_boundary . '"';
-			$last_boundary = $atc_boundary;
-		}
-
-		if ($this->attachmentsHaveMultipart('related'))
-		{
-			$rel_boundary        = uniqid('B_REL_', true);
-			$rel_boundary_header = 'Content-Type: multipart/related; boundary="' . $rel_boundary . '"';
-
-			if (isset($last_boundary))
-			{
-				$body .= '--' . $last_boundary . $this->newline . $rel_boundary_header;
-			}
-			else
-			{
-				$hdr .= $rel_boundary_header;
-			}
-
-			$last_boundary = $rel_boundary;
-		}
-
-		if ($this->getProtocol() === 'mail')
-		{
-			$this->headerStr .= $hdr;
-		}
-
-		static::strlen($body) && $body .= $this->newline . $this->newline;
-		$body                          .= $this->getMimeMessage() . $this->newline . $this->newline
-				. '--' . $last_boundary . $this->newline
-				. 'Content-Type: multipart/alternative; boundary="' . $alt_boundary . '"' . $this->newline . $this->newline
-				. '--' . $alt_boundary . $this->newline
-				. 'Content-Type: text/plain; charset=' . $this->charset . $this->newline
-				. 'Content-Transfer-Encoding: ' . $this->getEncoding() . $this->newline . $this->newline
-				. $this->getAltMessage() . $this->newline . $this->newline
-				. '--' . $alt_boundary . $this->newline
-				. 'Content-Type: text/html; charset=' . $this->charset . $this->newline
-				. 'Content-Transfer-Encoding: quoted-printable' . $this->newline . $this->newline
-				. $this->prepQuotedPrintable($this->body) . $this->newline . $this->newline
-				. '--' . $alt_boundary . '--' . $this->newline . $this->newline;
-
-		if (! empty($rel_boundary))
-		{
-			$body .= $this->newline . $this->newline;
-			$this->appendAttachments($body, $rel_boundary, 'related');
-		}
-
-		// multipart/mixed attachments
-		if (! empty($atc_boundary))
-		{
-			$body .= $this->newline . $this->newline;
-			$this->appendAttachments($body, $atc_boundary, 'mixed');
-		}
-
-		break;
-*/
-
-		return $message;
-	}
+    /**
+     * Protocol for this handler.
+     * Set by child classes.
+     *
+     * @var string
+     */
+    protected $protocol;
+
+    /**
+     * The Mailer config.
+     *
+     * @var Mailer|null
+     */
+    protected $config;
+
+    /**
+     * The config-specific Encode instance.
+     *
+     * @var Encode
+     */
+    protected $encode;
+
+    /**
+     * The config-specific Format instance.
+     *
+     * @var Format
+     */
+    protected $format;
+
+    /**
+     * Whether this handler is supported on this system.
+     */
+    abstract public function isSupported(): bool;
+
+    /**
+     * Spools an Email to the server.
+     *
+     * @return bool
+     */
+    abstract protected function spool(Email $email);
+
+    /**
+     * Stores the Mailer config and preps encoding and formatting.
+     */
+    public function __construct(Mailer $config)
+    {
+        helper(['text']);
+
+        $this->config = clone $config;
+        $this->encode = new Encode($this->config);
+        $this->format = new Format($this->config);
+
+        // Enforce a few config validations
+        $this->config->format    = in_array($this->config->format, ['html', 'text'], true) ? $this->config->format : 'text';
+        $this->config->wordWrap  = is_bool($this->config->wordWrap) ? $this->config->wordWrap : true;
+        $this->config->wrapChars = is_int($this->config->wrapChars) ? $this->config->wrapChars : 76;
+    }
+
+    /**
+     * Gets the Mailer config.
+     */
+    public function getConfig(Mailer $config): Mailer
+    {
+        return $this->config;
+    }
+
+    /**
+     * Gets the protocol.
+     */
+    public function getProtocol(): string
+    {
+        return $this->protocol;
+    }
+
+    /**
+     * Sends an Email.
+     */
+    public function send(Email $email)
+    {
+        $this->buildHeaders($email);
+        $this->buildMessage($email);
+
+        // Check for a batch request
+        if ($this->config->batchMode) {
+            // Temporarily disable batch mode to prevent recursion
+            $this->config->batchMode = false;
+            $bccs                    = $email->getBcc();
+
+            try {
+                foreach (array_chunk($bccs, $this->config->batchSize) as $bcc) {
+                    $batch = clone $email;
+                    $batch->bcc($bcc);
+
+                    $this->send($batch);
+                }
+            }
+            // Restore batch mode
+            finally {
+                $this->config->batchMode = true;
+            }
+
+            return;
+        }
+
+        return $this->spool($email);
+
+        /* WIP
+                if ($result)
+                {
+                    $this->setArchiveValues();
+
+                    if ($autoClear)
+                    {
+                        $this->clear();
+                    }
+
+                    Events::trigger('email_sent', $email);
+                }
+        */
+    }
+
+    /**
+     * Builds the remaining Email headers (including config defaults)
+     * and validates all required headers are present.
+     *
+     * @throws MailerException
+     *
+     * @return Mailer
+     */
+    protected function buildHeaders(Email $email): self
+    {
+        // Apply any missing defaults from the config
+        $email->set($this->config->defaults, false);
+
+        // Must have a sender
+        if (null === $email->getFrom()) {
+            throw MailerException::forNoFrom();
+        }
+        // Must have at least one recipient
+        if (empty($email->getTo()) && empty($email->getCc()) && empty($email->getBcc())) {
+            throw MailerException::forNoRecipients();
+        }
+
+        // If no "reply to" header was set then use the From value
+        if (null === $email->getReplyTo() && $from = $email->getFrom()) {
+            $email->setReplyTo($from);
+        }
+        // If no priority header was set then use "normal"
+        if (null === $email->getPriority()) {
+            $email->setPriority(3);
+        }
+
+        // Set transport headers directly
+        $email->setHeader('User-Agent', $this->config->userAgent);
+        $email->setHeader('X-Mailer', $this->config->userAgent);
+        $email->setHeader('X-Sender', $email->getFrom()->getEmail());
+        $email->setHeader('Message-ID', $email->getMessageID());
+        $email->setHeader('Mime-Version', '1.0');
+
+        // Content headers take a bit more calculating
+        $this->buildContentHeaders($email);
+
+        return $this;
+    }
+
+    /**
+     * Caculates and sets the Headers for Content-Type and Content-Transfer-Encoding.
+     *
+     * @param Email
+     *
+     * @return $this
+     */
+    protected function buildContentHeaders(Email $email): self
+    {
+        // If there are no attachments this is much easier
+        if ($email->getAttachments() === []) {
+            // text
+            if ($this->config->mailFormat === 'text') {
+                $email->setHeader('Content-Type', 'text/plain; charset=' . $this->encode->charset);
+                $email->setHeader('Content-Transfer-Encoding', 'text/plain; charset=' . $this->encode->charset);
+
+                return $this;
+            }
+
+            /**
+             * Version 3 edition supported forced multipart messages for html format despite
+             * it not being in the configuration or documentation. Should this feature need
+             * to be added back then this is the appropriate place.
+             */
+
+            // html
+            $email->setHeader('Content-Type', 'text/html; charset=' . $this->encode->charset);
+            $email->setHeader('Content-Transfer-Encoding', 'quoted-printable');
+
+            return $this;
+        }
+
+        // text + attachments
+        if ($this->config->mailFormat === 'text') {
+            $email->setHeader('Content-Type', 'multipart/mixed; boundary=' . $email->getBoundary('B_ATC'));
+
+            return $this;
+        }
+
+        // html + attachments
+        if ($email->getAttachments(false)) {
+            $email->setHeader('Content-Type', 'multipart/mixed; boundary=' . $email->getBoundary('B_ATC'));
+        }
+        if ($email->getAttachments(true)) {
+            $email->setHeader('Content-Type', 'multipart/related; boundary=' . $email->getBoundary('B_REL'));
+        }
+    }
+
+    /**
+     * Returns the string version of the Headers from the email.
+     * Split out for handlers that need to skip the subject.
+     *
+     * @param Email
+     */
+    protected function getHeaderString(Email $email): string
+    {
+        return $email->getHeaderString($this->config->newline);
+    }
+
+    /**
+     * Returns the string version of the message, including all headers and attachments.
+     *
+     * @param Email
+     */
+    protected function getMessageString(Email $email): string
+    {
+        $message = '';
+
+        // If there are no attachments this is much easier
+        if ($email->getAttachments() === []) {
+            // text
+            if ($this->config->format === 'text') {
+                $message .= $email->getHeaderString($this->config->newline, null, ['Content-Type', 'Content-Transfer-Encoding']);
+                $message .= $this->config->newline . $this->config->newline;
+                $message .= $this->config->wordWrap ? word_wrap($email->getBody()) : $email->getBody();
+
+                return $message;
+            }
+
+            // html
+            $message .= $email->getHeaderString($this->config->newline, null, ['Content-Type', 'Content-Transfer-Encoding']);
+            $message .= $this->config->newline . $this->config->newline;
+            $message .= $this->encode->quotedPrintable($email->getBody()) . $this->config->newline . $this->config->newline;
+
+            return $message;
+        }
+
+        // text + attachment
+        if ($this->config->format === 'text') {
+            $message .= $email->getHeaderString($this->config->newline, null, ['Content-Type']);
+            $message .= $this->config->newline . $this->config->newline;
+
+            $message .= lang('Mailer.mimeMessage', [$this->config->newline])
+                    . $this->config->newline . $this->config->newline
+                    . '--' . $email->getBoundary('B_ATC') . $this->config->newline
+                    . 'Content-Type: text/plain; charset=' . $this->encode->charset . $this->config->newline
+                    . 'Content-Transfer-Encoding: ' . $this->encode->encoding . $this->config->newline
+                    . $this->config->newline
+                    . $email->getBody() . $this->config->newline . $this->config->newline;
+
+            $this->appendAttachments($body, $boundary);
+
+            return $message;
+        }
+
+        // html + attachments
+
+        /* WIP
+                $alt_boundary  = uniqid('B_ALT_', true);
+                $last_boundary = null;
+
+                if ($this->attachmentsHaveMultipart('mixed'))
+                {
+                    $atc_boundary  = uniqid('B_ATC_', true);
+                    $hdr          .= 'Content-Type: multipart/mixed; boundary="' . $atc_boundary . '"';
+                    $last_boundary = $atc_boundary;
+                }
+
+                if ($this->attachmentsHaveMultipart('related'))
+                {
+                    $rel_boundary        = uniqid('B_REL_', true);
+                    $rel_boundary_header = 'Content-Type: multipart/related; boundary="' . $rel_boundary . '"';
+
+                    if (isset($last_boundary))
+                    {
+                        $body .= '--' . $last_boundary . $this->newline . $rel_boundary_header;
+                    }
+                    else
+                    {
+                        $hdr .= $rel_boundary_header;
+                    }
+
+                    $last_boundary = $rel_boundary;
+                }
+
+                if ($this->getProtocol() === 'mail')
+                {
+                    $this->headerStr .= $hdr;
+                }
+
+                static::strlen($body) && $body .= $this->newline . $this->newline;
+                $body                          .= $this->getMimeMessage() . $this->newline . $this->newline
+                        . '--' . $last_boundary . $this->newline
+                        . 'Content-Type: multipart/alternative; boundary="' . $alt_boundary . '"' . $this->newline . $this->newline
+                        . '--' . $alt_boundary . $this->newline
+                        . 'Content-Type: text/plain; charset=' . $this->charset . $this->newline
+                        . 'Content-Transfer-Encoding: ' . $this->getEncoding() . $this->newline . $this->newline
+                        . $this->getAltMessage() . $this->newline . $this->newline
+                        . '--' . $alt_boundary . $this->newline
+                        . 'Content-Type: text/html; charset=' . $this->charset . $this->newline
+                        . 'Content-Transfer-Encoding: quoted-printable' . $this->newline . $this->newline
+                        . $this->prepQuotedPrintable($this->body) . $this->newline . $this->newline
+                        . '--' . $alt_boundary . '--' . $this->newline . $this->newline;
+
+                if (! empty($rel_boundary))
+                {
+                    $body .= $this->newline . $this->newline;
+                    $this->appendAttachments($body, $rel_boundary, 'related');
+                }
+
+                // multipart/mixed attachments
+                if (! empty($atc_boundary))
+                {
+                    $body .= $this->newline . $this->newline;
+                    $this->appendAttachments($body, $atc_boundary, 'mixed');
+                }
+
+                break;
+        */
+
+        return $message;
+    }
 }
diff --git a/system/Mailer/Handlers/DummyHandler.php b/system/Mailer/Handlers/DummyHandler.php
index 3d879f16d9db..e3f3c30c21e5 100644
--- a/system/Mailer/Handlers/DummyHandler.php
+++ b/system/Mailer/Handlers/DummyHandler.php
@@ -1,12 +1,12 @@
 <?php
 
 /**
- * This file is part of the CodeIgniter 4 framework.
+ * This file is part of CodeIgniter 4 framework.
  *
  * (c) CodeIgniter Foundation <admin@codeigniter.com>
  *
- * For the full copyright and license information, please view the LICENSE
- * file that was distributed with this source code.
+ * For the full copyright and license information, please view
+ * the LICENSE file that was distributed with this source code.
  */
 
 namespace CodeIgniter\Mailer\Handlers;
@@ -15,24 +15,20 @@
 
 class DummyHandler extends BaseHandler
 {
-	/**
-	 * Whether this handler is supported on this system.
-	 *
-	 * @return boolean
-	 */
-	public function isSupported(): bool
-	{
-		return true;
-	}
+    /**
+     * Whether this handler is supported on this system.
+     */
+    public function isSupported(): bool
+    {
+        return true;
+    }
 
-	/**
-	 * Does not spools an Email to the server.
-	 *
-	 * @param Email $email
-	 *
-	 * @return boolean
-	 */
-	protected function spool(Email $email)
-	{
-	}
+    /**
+     * Does not spools an Email to the server.
+     *
+     * @return bool
+     */
+    protected function spool(Email $email)
+    {
+    }
 }
diff --git a/system/Mailer/Handlers/MailHandler.php b/system/Mailer/Handlers/MailHandler.php
index 5aa6a99d7e3b..b7e6d8c0ca4e 100644
--- a/system/Mailer/Handlers/MailHandler.php
+++ b/system/Mailer/Handlers/MailHandler.php
@@ -1,20 +1,19 @@
 <?php
 
 /**
- * This file is part of the CodeIgniter 4 framework.
+ * This file is part of CodeIgniter 4 framework.
  *
  * (c) CodeIgniter Foundation <admin@codeigniter.com>
  *
- * For the full copyright and license information, please view the LICENSE
- * file that was distributed with this source code.
+ * For the full copyright and license information, please view
+ * the LICENSE file that was distributed with this source code.
  */
 
 namespace CodeIgniter\Mailer\Handlers;
 
 use CodeIgniter\Mailer\Email;
 use CodeIgniter\Mailer\Exceptions\MailerException;
-use Config\Mimes;
-use Psr\Log\LoggerAwareTrait;
+use ErrorException;
 
 /**
  * Mail Handler
@@ -23,94 +22,80 @@
  */
 class MailHandler extends BaseHandler
 {
-	/**
-	 * Protocol for this handler.
-	 *
-	 * @var string
-	 */
-	protected $protocol = 'mail';
-
-	/**
-	 * Whether this handler is supported on this system.
-	 *
-	 * @return boolean
-	 */
-	public function isSupported(): bool
-	{
-		return function_exists('mail');
-	}
-
-	/**
-	 * Returns the string version of the Headers from the email,
-	 * appending a newline and excluding 'Subject' (mail() handles it directly).
-	 *
-	 * @param Email
-	 *
-	 * @return string
-	 */
-	protected function getHeaderString(Email $email): string
-	{
-		return $email->getHeaderString($this->config->newline, ['Subject']) . $this->conifg->newline;
-	}
-
-/* WIP */
-
-	/**
-	 * Spools an Email to the server.
-	 *
-	 * @param Email $email
-	 *
-	 * @return boolean
-	 */
-	protected function spool(Email $email)
-	{
-		$this->unwrapSpecials();
-
-		try
-		{
-			$success = $this->sendWithMail();
-		}
-		catch (\ErrorException $e)
-		{
-			$success = false;
-			$this->logger->error('Mailer: ' . $method . ' throwed ' . $e->getMessage());
-		}
-
-		if (! $success)
-		{
-			throw MailerException::forSendFailure($protocol === 'mail' ? 'PHPMail' : ucfirst($protocol));
-		}
-
-		$this->setErrorMessage(lang('Mailer.sent', [$protocol]));
-
-		return true;
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Send using mail()
-	 *
-	 * @return boolean
-	 */
-	protected function sendWithMail()
-	{
-		if (is_array($this->recipients))
-		{
-			$this->recipients = implode(', ', $this->recipients);
-		}
-
-		// _validate_email_for_shell() below accepts by reference,
-		// so this needs to be assigned to a variable
-		$from = $this->cleanEmail($this->headers['Return-Path']);
-
-		if (! $this->validateEmailForShell($from))
-		{
-			return mail($this->recipients, $this->subject, $this->finalBody, $this->headerStr);
-		}
-
-		// most documentation of sendmail using the "-f" flag lacks a space after it, however
-		// we've encountered servers that seem to require it to be in place.
-		return mail($this->recipients, $this->subject, $this->finalBody, $this->headerStr, '-f ' . $from);
-	}
+    /**
+     * Protocol for this handler.
+     *
+     * @var string
+     */
+    protected $protocol = 'mail';
+
+    /**
+     * Whether this handler is supported on this system.
+     */
+    public function isSupported(): bool
+    {
+        return function_exists('mail');
+    }
+
+    /**
+     * Returns the string version of the Headers from the email,
+     * appending a newline and excluding 'Subject' (mail() handles it directly).
+     *
+     * @param Email
+     */
+    protected function getHeaderString(Email $email): string
+    {
+        return $email->getHeaderString($this->config->newline, ['Subject']) . $this->conifg->newline;
+    }
+
+    // WIP
+
+    /**
+     * Spools an Email to the server.
+     *
+     * @return bool
+     */
+    protected function spool(Email $email)
+    {
+        $this->unwrapSpecials();
+
+        try {
+            $success = $this->sendWithMail();
+        } catch (ErrorException $e) {
+            $success = false;
+            $this->logger->error('Mailer: ' . $method . ' throwed ' . $e->getMessage());
+        }
+
+        if (! $success) {
+            throw MailerException::forSendFailure($protocol === 'mail' ? 'PHPMail' : ucfirst($protocol));
+        }
+
+        $this->setErrorMessage(lang('Mailer.sent', [$protocol]));
+
+        return true;
+    }
+
+    /**
+     * Send using mail()
+     *
+     * @return bool
+     */
+    protected function sendWithMail()
+    {
+        if (is_array($this->recipients)) {
+            $this->recipients = implode(', ', $this->recipients);
+        }
+
+        // _validate_email_for_shell() below accepts by reference,
+        // so this needs to be assigned to a variable
+        $from = $this->cleanEmail($this->headers['Return-Path']);
+
+        if (! $this->validateEmailForShell($from)) {
+            return mail($this->recipients, $this->subject, $this->finalBody, $this->headerStr);
+        }
+
+        // most documentation of sendmail using the "-f" flag lacks a space after it, however
+        // we've encountered servers that seem to require it to be in place.
+        return mail($this->recipients, $this->subject, $this->finalBody, $this->headerStr, '-f ' . $from);
+    }
 }
diff --git a/system/Mailer/Handlers/SMTPHandler.php b/system/Mailer/Handlers/SMTPHandler.php
index eaeefa52d5de..f79d7a64a273 100644
--- a/system/Mailer/Handlers/SMTPHandler.php
+++ b/system/Mailer/Handlers/SMTPHandler.php
@@ -1,4 +1,14 @@
 <?php
+
+/**
+ * This file is part of CodeIgniter 4 framework.
+ *
+ * (c) CodeIgniter Foundation <admin@codeigniter.com>
+ *
+ * For the full copyright and license information, please view
+ * the LICENSE file that was distributed with this source code.
+ */
+
 namespace CodeIgniter\Mailer\Handlers;
 
 /**
@@ -28,12 +38,11 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  *
- * @package    CodeIgniter
- * @author     EllisLab Dev Team
  * @copyright  Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
  * @copyright  Copyright (c) 2014 - 2018, British Columbia Institute of Technology (http://bcit.ca/)
  * @license    http://opensource.org/licenses/MIT    MIT License
- * @link       https://codeigniter.com
+ *
+ * @see       https://codeigniter.com
  * @since      Version 1.0.0
  * @filesource
  */
@@ -41,1598 +50,1431 @@
 use CodeIgniter\Mailer\Email;
 use CodeIgniter\Mailer\Exceptions\MailerException;
 use Config\Mimes;
-use Psr\Log\LoggerAwareTrait;
+use ErrorException;
 
 /**
  * SMTP Mailer
  *
  * Permits a Message to be sent using SMTP.
  *
- * @package    CodeIgniter
- * @subpackage Libraries
  * @category   Libraries
- * @author     EllisLab Dev Team
- * @link       https://codeigniter.com/user_guide/libraries/email.html
+ *
+ * @see       https://codeigniter.com/user_guide/libraries/email.html
  */
 class SMTPHandler extends BaseHandler
 {
-
-	/**
-	 * Message format.
-	 *
-	 * @var string 'text' or 'html'
-	 */
-	public $mailType = 'text';
-
-	/**
-	 * Character set (default: utf-8)
-	 *
-	 * @var string
-	 */
-	public $charset = 'utf-8';
-
-	/**
-	 * Alternative message (for HTML messages only)
-	 *
-	 * @var string
-	 */
-	public $altMessage = '';
-
-	/**
-	 * Whether to validate email addresses.
-	 *
-	 * @var boolean
-	 */
-	public $validate = true;
-
-	/**
-	 * X-Priority header value.
-	 *
-	 * @var integer 1-5
-	 */
-	public $priority = 3;            // Default priority (1 - 5)
-
-	/**
-	 * Newline character sequence.
-	 * Use "\r\n" to comply with RFC 822.
-	 *
-	 * @link http://www.ietf.org/rfc/rfc822.txt
-	 * @var  string "\r\n" or "\n"
-	 */
-	public $newline = "\n";            // Default newline. "\r\n" or "\n" (Use "\r\n" to comply with RFC 822)
-
-	/**
-	 * CRLF character sequence
-	 *
-	 * RFC 2045 specifies that for 'quoted-printable' encoding,
-	 * "\r\n" must be used. However, it appears that some servers
-	 * (even on the receiving end) don't handle it properly and
-	 * switching to "\n", while improper, is the only solution
-	 * that seems to work for all environments.
-	 *
-	 * @link http://www.ietf.org/rfc/rfc822.txt
-	 * @var  string
-	 */
-	public $CRLF = "\n";
-
-	/**
-	 * Whether to use Delivery Status Notification.
-	 *
-	 * @var boolean
-	 */
-	public $DSN = false;
-
-	/**
-	 * Whether to send multipart alternatives.
-	 * Yahoo! doesn't seem to like these.
-	 *
-	 * @var boolean
-	 */
-	public $sendMultipart = true;
-
-	/**
-	 * Whether to send messages to BCC recipients in batches.
-	 *
-	 * @var boolean
-	 */
-	public $BCCBatchMode = false;
-
-	/**
-	 * BCC Batch max number size.
-	 *
-	 * @see Mailer::$BCCBatchMode
-	 * @var integer
-	 */
-	public $BCCBatchSize = 200;
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Subject header
-	 *
-	 * @var string
-	 */
-	protected $subject = '';
-
-	/**
-	 * Message body
-	 *
-	 * @var string
-	 */
-	protected $body = '';
-
-	/**
-	 * Final message body to be sent.
-	 *
-	 * @var string
-	 */
-	protected $finalBody = '';
-
-	/**
-	 * Final headers to send
-	 *
-	 * @var string
-	 */
-	protected $headerStr = '';
-
-	/**
-	 * SMTP Connection socket placeholder
-	 *
-	 * @var resource
-	 */
-	protected $SMTPConnect = '';
-
-	/**
-	 * Mail encoding
-	 *
-	 * @var string '8bit' or '7bit'
-	 */
-	protected $encoding = '8bit';
-
-	/**
-	 * Whether to send a Reply-To header
-	 *
-	 * @var boolean
-	 */
-	protected $replyToFlag = false;
-
-	/**
-	 * Debug messages
-	 *
-	 * @see Mailer::printDebugger()
-	 * @var array
-	 */
-	protected $debugMessage = [];
-
-	/**
-	 * Recipients
-	 *
-	 * @var array
-	 */
-	protected $recipients = [];
-
-	/**
-	 * CC Recipients
-	 *
-	 * @var array
-	 */
-	protected $CCArray = [];
-
-	/**
-	 * BCC Recipients
-	 *
-	 * @var array
-	 */
-	protected $BCCArray = [];
-
-	/**
-	 * Message headers
-	 *
-	 * @var array
-	 */
-	protected $headers = [];
-
-	/**
-	 * Attachment data
-	 *
-	 * @var array
-	 */
-	protected $attachments = [];
-
-	/**
-	 * Valid $protocol values
-	 *
-	 * @see Mailer::$protocol
-	 * @var array
-	 */
-	protected $protocols = [
-		'mail',
-		'sendmail',
-		'smtp',
-	];
-
-	/**
-	 * Base charsets
-	 *
-	 * Character sets valid for 7-bit encoding,
-	 * excluding language suffix.
-	 *
-	 * @var array
-	 */
-	protected $baseCharsets = [
-		'us-ascii',
-		'iso-2022-',
-	];
-
-	/**
-	 * Bit depths
-	 *
-	 * Valid mail encodings
-	 *
-	 * @see Mailer::$encoding
-	 * @var array
-	 */
-	protected $bitDepths = [
-		'7bit',
-		'8bit',
-	];
-
-	/**
-	 * $priority translations
-	 *
-	 * Actual values to send with the X-Priority header
-	 *
-	 * @var array
-	 */
-	protected $priorities = [
-		1 => '1 (Highest)',
-		2 => '2 (High)',
-		3 => '3 (Normal)',
-		4 => '4 (Low)',
-		5 => '5 (Lowest)',
-	];
-
-	/**
-	 * mbstring.func_overload flag
-	 *
-	 * @var boolean
-	 */
-	protected static $func_overload;
-
-	/**
-	 * Logger instance to record error messages and awarnings.
-	 *
-	 * @var \PSR\Log\LoggerInterface
-	 */
-	protected $logger;
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Constructor - Sets Mailer Preferences
-	 *
-	 * The constructor can be passed an array of config values
-	 *
-	 * @param array|null $config
-	 */
-	public function __construct($config = null)
-	{
-		$this->protocol = 'smtp';
-		$this->initialize($config);
-
-		log_message('info', 'Mailer Class Initialized');
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Initialize preferences
-	 *
-	 * @param array|\Config\Mailer $config
-	 *
-	 * @return Mailer
-	 */
-	public function initialize($config)
-	{
-		$this->clear();
-
-		if ($config instanceof \Config\Mailer)
-		{
-			$config = get_object_vars($config);
-		}
-
-		foreach (get_class_vars(get_class($this)) as $key => $value)
-		{
-			if (property_exists($this, $key) && isset($config[$key]))
-			{
-				$method = 'set' . ucfirst($key);
-
-				if (method_exists($this, $method))
-				{
-					$this->$method($config[$key]);
-				}
-				else
-				{
-					$this->$key = $config[$key];
-				}
-			}
-		}
-
-		$this->charset  = strtoupper($this->charset);
-		$this->SMTPAuth = isset($this->SMTPUser[0], $this->SMTPPass[0]);
-
-		return $this;
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Initialize the Mailer Data
-	 *
-	 * @param boolean $clearAttachments
-	 *
-	 * @return Mailer
-	 */
-	public function clear($clearAttachments = false)
-	{
-		$this->subject      = '';
-		$this->body         = '';
-		$this->finalBody    = '';
-		$this->headerStr    = '';
-		$this->replyToFlag  = false;
-		$this->recipients   = [];
-		$this->CCArray      = [];
-		$this->BCCArray     = [];
-		$this->headers      = [];
-		$this->debugMessage = [];
-
-		//      $this->setHeader('Date', $this->setDate());
-
-		if ($clearAttachments !== false)
-		{
-			$this->attachments = [];
-		}
-
-		return $this;
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Build final headers
-	 */
-	protected function buildHeaders()
-	{
-		$this->setHeader('User-Agent', $this->userAgent);
-		$this->setHeader('X-Sender', $this->cleanEmail($this->headers['From']));
-		$this->setHeader('X-Mailer', $this->userAgent);
-		$this->setHeader('X-Priority', $this->priorities[$this->priority]);
-		$this->setHeader('Message-ID', $this->getMessageID());
-		$this->setHeader('Mime-Version', '1.0');
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Write Headers as a string
-	 */
-	protected function writeHeaders()
-	{
-		if ($this->protocol === 'mail')
-		{
-			if (isset($this->headers['Subject']))
-			{
-				$this->subject = $this->headers['Subject'];
-				unset($this->headers['Subject']);
-			}
-		}
-
-		reset($this->headers);
-		$this->headerStr = '';
-
-		foreach ($this->headers as $key => $val)
-		{
-			$val = trim($val);
-
-			if ($val !== '')
-			{
-				$this->headerStr .= $key . ': ' . $val . $this->newline;
-			}
-		}
-
-		if ($this->getProtocol() === 'mail')
-		{
-			$this->headerStr = rtrim($this->headerStr);
-		}
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Build Final Body and attachments
-	 */
-	protected function buildMessage()
-	{
-		if ($this->wordWrap === true && $this->mailType !== 'html')
-		{
-			$this->body = $this->wordWrap($this->body);
-		}
-
-		$this->writeHeaders();
-
-		$hdr  = ($this->getProtocol() === 'mail') ? $this->newline : '';
-		$body = '';
-
-		switch ($this->getContentType())
-		{
-			case 'plain':
-
-				$hdr .= 'Content-Type: text/plain; charset=' . $this->charset . $this->newline
-						. 'Content-Transfer-Encoding: ' . $this->getEncoding();
-
-				if ($this->getProtocol() === 'mail')
-				{
-					$this->headerStr .= $hdr;
-					$this->finalBody  = $this->body;
-				}
-				else
-				{
-					$this->finalBody = $hdr . $this->newline . $this->newline . $this->body;
-				}
-
-				return;
-
-			case 'html':
-
-				if ($this->sendMultipart === false)
-				{
-					$hdr .= 'Content-Type: text/html; charset=' . $this->charset . $this->newline
-							. 'Content-Transfer-Encoding: quoted-printable';
-				}
-				else
-				{
-					$boundary = uniqid('B_ALT_', true);
-					$hdr     .= 'Content-Type: multipart/alternative; boundary="' . $boundary . '"';
-
-					$body .= $this->getMimeMessage() . $this->newline . $this->newline
-							. '--' . $boundary . $this->newline
-							. 'Content-Type: text/plain; charset=' . $this->charset . $this->newline
-							. 'Content-Transfer-Encoding: ' . $this->getEncoding() . $this->newline . $this->newline
-							. $this->getAltMessage() . $this->newline . $this->newline
-							. '--' . $boundary . $this->newline
-							. 'Content-Type: text/html; charset=' . $this->charset . $this->newline
-							. 'Content-Transfer-Encoding: quoted-printable' . $this->newline . $this->newline;
-				}
-
-				$this->finalBody = $body . $this->prepQuotedPrintable($this->body) . $this->newline . $this->newline;
-
-				if ($this->getProtocol() === 'mail')
-				{
-					$this->headerStr .= $hdr;
-				}
-				else
-				{
-					$this->finalBody = $hdr . $this->newline . $this->newline . $this->finalBody;
-				}
-
-				if ($this->sendMultipart !== false)
-				{
-					$this->finalBody .= '--' . $boundary . '--';
-				}
-
-				return;
-
-			case 'plain-attach':
-
-				$boundary = uniqid('B_ATC_', true);
-				$hdr     .= 'Content-Type: multipart/mixed; boundary="' . $boundary . '"';
-
-				if ($this->getProtocol() === 'mail')
-				{
-					$this->headerStr .= $hdr;
-				}
-
-				$body .= $this->getMimeMessage() . $this->newline
-						. $this->newline
-						. '--' . $boundary . $this->newline
-						. 'Content-Type: text/plain; charset=' . $this->charset . $this->newline
-						. 'Content-Transfer-Encoding: ' . $this->getEncoding() . $this->newline
-						. $this->newline
-						. $this->body . $this->newline . $this->newline;
-
-				$this->appendAttachments($body, $boundary);
-
-				break;
-			case 'html-attach':
-
-				$alt_boundary  = uniqid('B_ALT_', true);
-				$last_boundary = null;
-
-				if ($this->attachmentsHaveMultipart('mixed'))
-				{
-					$atc_boundary  = uniqid('B_ATC_', true);
-					$hdr          .= 'Content-Type: multipart/mixed; boundary="' . $atc_boundary . '"';
-					$last_boundary = $atc_boundary;
-				}
-
-				if ($this->attachmentsHaveMultipart('related'))
-				{
-					$rel_boundary        = uniqid('B_REL_', true);
-					$rel_boundary_header = 'Content-Type: multipart/related; boundary="' . $rel_boundary . '"';
-
-					if (isset($last_boundary))
-					{
-						$body .= '--' . $last_boundary . $this->newline . $rel_boundary_header;
-					}
-					else
-					{
-						$hdr .= $rel_boundary_header;
-					}
-
-					$last_boundary = $rel_boundary;
-				}
-
-				if ($this->getProtocol() === 'mail')
-				{
-					$this->headerStr .= $hdr;
-				}
-
-				static::strlen($body) && $body .= $this->newline . $this->newline;
-				$body                          .= $this->getMimeMessage() . $this->newline . $this->newline
-						. '--' . $last_boundary . $this->newline
-						. 'Content-Type: multipart/alternative; boundary="' . $alt_boundary . '"' . $this->newline . $this->newline
-						. '--' . $alt_boundary . $this->newline
-						. 'Content-Type: text/plain; charset=' . $this->charset . $this->newline
-						. 'Content-Transfer-Encoding: ' . $this->getEncoding() . $this->newline . $this->newline
-						. $this->getAltMessage() . $this->newline . $this->newline
-						. '--' . $alt_boundary . $this->newline
-						. 'Content-Type: text/html; charset=' . $this->charset . $this->newline
-						. 'Content-Transfer-Encoding: quoted-printable' . $this->newline . $this->newline
-						. $this->prepQuotedPrintable($this->body) . $this->newline . $this->newline
-						. '--' . $alt_boundary . '--' . $this->newline . $this->newline;
-
-				if (! empty($rel_boundary))
-				{
-					$body .= $this->newline . $this->newline;
-					$this->appendAttachments($body, $rel_boundary, 'related');
-				}
-
-				// multipart/mixed attachments
-				if (! empty($atc_boundary))
-				{
-					$body .= $this->newline . $this->newline;
-					$this->appendAttachments($body, $atc_boundary, 'mixed');
-				}
-
-				break;
-		}
-
-		$this->finalBody = ($this->getProtocol() === 'mail') ? $body : $hdr . $this->newline . $this->newline . $body;
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Prepares attachment string
-	 *
-	 * @param string      &$body     Message body to append to
-	 * @param string      $boundary  Multipart boundary
-	 * @param string|null $multipart When provided, only attachments of this type will be processed
-	 *
-	 * @return string
-	 */
-	protected function appendAttachments(&$body, $boundary, $multipart = null)
-	{
-		for ($i = 0, $c = count($this->attachments); $i < $c; $i ++)
-		{
-			if (isset($multipart) && $this->attachments[$i]['multipart'] !== $multipart)
-			{
-				continue;
-			}
-
-			$name = isset($this->attachments[$i]['name'][1]) ? $this->attachments[$i]['name'][1] : basename($this->attachments[$i]['name'][0]);
-
-			$body .= '--' . $boundary . $this->newline
-					. 'Content-Type: ' . $this->attachments[$i]['type'] . '; name="' . $name . '"' . $this->newline
-					. 'Content-Disposition: ' . $this->attachments[$i]['disposition'] . ';' . $this->newline
-					. 'Content-Transfer-Encoding: base64' . $this->newline
-					. (empty($this->attachments[$i]['cid']) ? '' : 'Content-ID: <' . $this->attachments[$i]['cid'] . '>' . $this->newline)
-					. $this->newline
-					. $this->attachments[$i]['content'] . $this->newline;
-		}
-
-		// $name won't be set if no attachments were appended,
-		// and therefore a boundary wouldn't be necessary
-		empty($name) || $body .= '--' . $boundary . '--';
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Prep Quoted Printable
-	 *
-	 * Prepares string for Quoted-Printable Content-Transfer-Encoding
-	 * Refer to RFC 2045 http://www.ietf.org/rfc/rfc2045.txt
-	 *
-	 * @param string $str
-	 *
-	 * @return string
-	 */
-	protected function prepQuotedPrintable($str)
-	{
-		// ASCII code numbers for "safe" characters that can always be
-		// used literally, without encoding, as described in RFC 2049.
-		// http://www.ietf.org/rfc/rfc2049.txt
-		static $ascii_safe_chars = [
-			// ' (  )   +   ,   -   .   /   :   =   ?
-			39,
-			40,
-			41,
-			43,
-			44,
-			45,
-			46,
-			47,
-			58,
-			61,
-			63,
-			// numbers
-			48,
-			49,
-			50,
-			51,
-			52,
-			53,
-			54,
-			55,
-			56,
-			57,
-			// upper-case letters
-			65,
-			66,
-			67,
-			68,
-			69,
-			70,
-			71,
-			72,
-			73,
-			74,
-			75,
-			76,
-			77,
-			78,
-			79,
-			80,
-			81,
-			82,
-			83,
-			84,
-			85,
-			86,
-			87,
-			88,
-			89,
-			90,
-			// lower-case letters
-			97,
-			98,
-			99,
-			100,
-			101,
-			102,
-			103,
-			104,
-			105,
-			106,
-			107,
-			108,
-			109,
-			110,
-			111,
-			112,
-			113,
-			114,
-			115,
-			116,
-			117,
-			118,
-			119,
-			120,
-			121,
-			122,
-		];
-
-		// We are intentionally wrapping so mail servers will encode characters
-		// properly and MUAs will behave, so {unwrap} must go!
-		$str = str_replace(['{unwrap}', '{/unwrap}'], '', $str);
-
-		// RFC 2045 specifies CRLF as "\r\n".
-		// However, many developers choose to override that and violate
-		// the RFC rules due to (apparently) a bug in MS Exchange,
-		// which only works with "\n".
-		if ($this->CRLF === "\r\n")
-		{
-			return quoted_printable_encode($str);
-		}
-
-		// Reduce multiple spaces & remove nulls
-		$str = preg_replace(['| +|', '/\x00+/'], [' ', ''], $str);
-
-		// Standardize newlines
-		if (strpos($str, "\r") !== false)
-		{
-			$str = str_replace(["\r\n", "\r"], "\n", $str);
-		}
-
-		$escape = '=';
-		$output = '';
-
-		foreach (explode("\n", $str) as $line)
-		{
-			$length = static::strlen($line);
-			$temp   = '';
-
-			// Loop through each character in the line to add soft-wrap
-			// characters at the end of a line " =\r\n" and add the newly
-			// processed line(s) to the output (see comment on $crlf class property)
-			for ($i = 0; $i < $length; $i ++)
-			{
-				// Grab the next character
-				$char  = $line[$i];
-				$ascii = ord($char);
-
-				// Convert spaces and tabs but only if it's the end of the line
-				if ($ascii === 32 || $ascii === 9)
-				{
-					if ($i === ($length - 1))
-					{
-						$char = $escape . sprintf('%02s', dechex($ascii));
-					}
-				}
-				// DO NOT move this below the $ascii_safe_chars line!
-				//
-				// = (equals) signs are allowed by RFC2049, but must be encoded
-				// as they are the encoding delimiter!
-				elseif ($ascii === 61)
-				{
-					$char = $escape . strtoupper(sprintf('%02s', dechex($ascii)));  // =3D
-				}
-				elseif (! in_array($ascii, $ascii_safe_chars, true))
-				{
-					$char = $escape . strtoupper(sprintf('%02s', dechex($ascii)));
-				}
-
-				// If we're at the character limit, add the line to the output,
-				// reset our temp variable, and keep on chuggin'
-				if ((static::strlen($temp) + static::strlen($char)) >= 76)
-				{
-					$output .= $temp . $escape . $this->CRLF;
-					$temp    = '';
-				}
-
-				// Add the character to our temporary line
-				$temp .= $char;
-			}
-
-			// Add our completed line to the output
-			$output .= $temp . $this->CRLF;
-		}
-
-		// get rid of extra CRLF tacked onto the end
-		return static::substr($output, 0, static::strlen($this->CRLF) * -1);
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Prep Q Encoding
-	 *
-	 * Performs "Q Encoding" on a string for use in email headers.
-	 * It's related but not identical to quoted-printable, so it has its
-	 * own method.
-	 *
-	 * @param string $str
-	 *
-	 * @return string
-	 */
-	protected function prepQEncoding($str)
-	{
-		$str = str_replace(["\r", "\n"], '', $str);
-
-		if ($this->charset === 'UTF-8')
-		{
-			// Note: We used to have mb_encode_mimeheader() as the first choice
-			//       here, but it turned out to be buggy and unreliable. DO NOT
-			//       re-add it! -- Narf
-			if (extension_loaded('iconv'))
-			{
-				$output = @iconv_mime_encode(
-								'', $str, [
-									'scheme'           => 'Q',
-									'line-length'      => 76,
-									'input-charset'    => $this->charset,
-									'output-charset'   => $this->charset,
-									'line-break-chars' => $this->CRLF,
-								]);
-
-				// There are reports that iconv_mime_encode() might fail and return FALSE
-				if ($output !== false)
-				{
-					// iconv_mime_encode() will always put a header field name.
-					// We've passed it an empty one, but it still prepends our
-					// encoded string with ': ', so we need to strip it.
-					return static::substr($output, 2);
-				}
-
-				$chars = iconv_strlen($str, 'UTF-8');
-			}
-			elseif (extension_loaded('mbstring'))
-			{
-				$chars = mb_strlen($str, 'UTF-8');
-			}
-		}
-
-		// We might already have this set for UTF-8
-		isset($chars) || $chars = static::strlen($str);
-
-		$output = '=?' . $this->charset . '?Q?';
-		for ($i = 0, $length = static::strlen($output); $i < $chars; $i ++)
-		{
-			$chr = ($this->charset === 'UTF-8' && ICONV_ENABLED === true) ? '=' . implode('=', str_split(strtoupper(bin2hex(iconv_substr($str, $i, 1, $this->charset))), 2)) : '=' . strtoupper(bin2hex($str[$i]));
-
-			// RFC 2045 sets a limit of 76 characters per line.
-			// We'll append ?= to the end of each line though.
-			if ($length + ($l = static::strlen($chr)) > 74)
-			{
-				$output .= '?=' . $this->CRLF // EOL
-						. ' =?' . $this->charset . '?Q?' . $chr; // New line
-				$length  = 6 + static::strlen($this->charset) + $l; // Reset the length for the new line
-			}
-			else
-			{
-				$output .= $chr;
-				$length += $l;
-			}
-		}
-
-		// End the header
-		return $output . '?=';
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Send the Message
-	 *
-	 * @param Email $email
-	 *
-	 * @return boolean
-	 */
-	public function send(Email $email)
-	{
-		if (! isset($this->headers['From']) && ! empty($this->fromEmail))
-		{
-			$this->setFrom($this->fromEmail, $this->fromName);
-		}
-
-		if (! isset($this->headers['From']))
-		{
-			throw MailerException::forNoFrom();
-		}
-
-		if ($this->replyToFlag === false)
-		{
-			$this->setReplyTo($this->headers['From']);
-		}
-
-		if (empty($this->recipients) && ! isset($this->headers['To']) && empty($this->BCCArray) && ! isset($this->headers['Bcc']) && ! isset($this->headers['Cc'])
-		)
-		{
-			throw MailerException::forNoRecipients();
-		}
-
-		$this->buildHeaders();
-
-		if ($this->BCCBatchMode && count($this->BCCArray) > $this->BCCBatchSize)
-		{
-			$this->batchBCCSend();
-
-			if ($autoClear)
-			{
-				$this->clear();
-			}
-
-			return true;
-		}
-
-		$this->buildMessage();
-		$result = $this->spoolEmail();
-
-		if ($result && $autoClear)
-		{
-			$this->clear();
-		}
-
-		return $result;
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Batch Bcc Send. Sends groups of BCCs in batches
-	 */
-	public function batchBCCSend()
-	{
-		$float = $this->BCCBatchSize - 1;
-		$set   = '';
-		$chunk = [];
-
-		for ($i = 0, $c = count($this->BCCArray); $i < $c; $i ++)
-		{
-			if (isset($this->BCCArray[$i]))
-			{
-				$set .= ', ' . $this->BCCArray[$i];
-			}
-
-			if ($i === $float)
-			{
-				$chunk[] = static::substr($set, 1);
-				$float  += $this->BCCBatchSize;
-				$set     = '';
-			}
-
-			if ($i === $c - 1)
-			{
-				$chunk[] = static::substr($set, 1);
-			}
-		}
-
-		for ($i = 0, $c = count($chunk); $i < $c; $i ++)
-		{
-			unset($this->headers['Bcc']);
-
-			$bcc = $this->cleanEmail($this->stringToArray($chunk[$i]));
-
-			if ($this->protocol !== 'smtp')
-			{
-				$this->setHeader('Bcc', implode(', ', $bcc));
-			}
-			else
-			{
-				$this->BCCArray = $bcc;
-			}
-
-			$this->buildMessage();
-			$this->spoolEmail();
-		}
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Unwrap special elements
-	 */
-	protected function unwrapSpecials()
-	{
-		$this->finalBody = preg_replace_callback(
-				'/\{unwrap\}(.*?)\{\/unwrap\}/si', [
-					$this,
-					'removeNLCallback',
-				], $this->finalBody
-		);
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Strip line-breaks via callback
-	 *
-	 * @param string $matches
-	 *
-	 * @return string
-	 */
-	protected function removeNLCallback($matches)
-	{
-		if (strpos($matches[1], "\r") !== false || strpos($matches[1], "\n") !== false)
-		{
-			$matches[1] = str_replace(["\r\n", "\r", "\n"], '', $matches[1]);
-		}
-
-		return $matches[1];
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Spool mail to the mail server
-	 *
-	 * @return boolean
-	 */
-	protected function spoolEmail()
-	{
-		$this->unwrapSpecials();
-
-		$protocol = $this->getProtocol();
-		$method   = 'sendWith' . ucfirst($protocol);
-		try
-		{
-			$success = $this->$method();
-		}
-		catch (\ErrorException $e)
-		{
-			$success = false;
-			$this->logger->error('Mailer: ' . $method . ' throwed ' . $e->getMessage());
-		}
-
-		if (! $success)
-		{
-			throw MailerException::forSendFailure($protocol === 'mail' ? 'PHPMail' : ucfirst($protocol));
-		}
-
-		$this->setErrorMessage(lang('Mailer.sent', [$protocol]));
-
-		return true;
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Validate email for shell
-	 *
-	 * Applies stricter, shell-safe validation to email addresses.
-	 * Introduced to prevent RCE via sendmail's -f option.
-	 *
-	 * @see     https://github.com/codeigniter4/CodeIgniter/issues/4963
-	 * @see     https://gist.github.com/Zenexer/40d02da5e07f151adeaeeaa11af9ab36
-	 * @license https://creativecommons.org/publicdomain/zero/1.0/    CC0 1.0, Public Domain
-	 *
-	 * Credits for the base concept go to Paul Buonopane <paul@namepros.com>
-	 *
-	 * @param string &$email
-	 *
-	 * @return boolean
-	 */
-	protected function validateEmailForShell(&$email)
-	{
-		if (function_exists('idn_to_ascii') && $atpos = strpos($email, '@'))
-		{
-			$email = static::substr($email, 0, ++ $atpos) . idn_to_ascii(
-							static::substr($email, $atpos), 0, INTL_IDNA_VARIANT_UTS46
-			);
-		}
-
-		return (filter_var($email, FILTER_VALIDATE_EMAIL) === $email && preg_match('#\A[a-z0-9._+-]+@[a-z0-9.-]{1,253}\z#i', $email));
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Send using mail()
-	 *
-	 * @return boolean
-	 */
-	protected function sendWithMail()
-	{
-		if (is_array($this->recipients))
-		{
-			$this->recipients = implode(', ', $this->recipients);
-		}
-
-		// _validate_email_for_shell() below accepts by reference,
-		// so this needs to be assigned to a variable
-		$from = $this->cleanEmail($this->headers['Return-Path']);
-
-		if (! $this->validateEmailForShell($from))
-		{
-			return mail($this->recipients, $this->subject, $this->finalBody, $this->headerStr);
-		}
-
-		// most documentation of sendmail using the "-f" flag lacks a space after it, however
-		// we've encountered servers that seem to require it to be in place.
-		return mail($this->recipients, $this->subject, $this->finalBody, $this->headerStr, '-f ' . $from);
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Send using Sendmail
-	 *
-	 * @return boolean
-	 */
-	protected function sendWithSendmail()
-	{
-		// _validate_email_for_shell() below accepts by reference,
-		// so this needs to be assigned to a variable
-		$from = $this->cleanEmail($this->headers['From']);
-		if ($this->validateEmailForShell($from))
-		{
-			$from = '-f ' . $from;
-		}
-		else
-		{
-			$from = '';
-		}
-
-		// is popen() enabled?
-		if (! function_usable('popen') || false === ($fp = @popen($this->mailPath . ' -oi ' . $from . ' -t', 'w')))
-		{
-			// server probably has popen disabled, so nothing we can do to get a verbose error.
-			return false;
-		}
-
-		fputs($fp, $this->headerStr);
-		fputs($fp, $this->finalBody);
-
-		$status = pclose($fp);
-
-		if ($status !== 0)
-		{
-			throw MailerException::forNosocket($status);
-		}
-
-		return true;
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Send using SMTP
-	 *
-	 * @return boolean
-	 */
-	protected function sendWithSmtp()
-	{
-		if ($this->SMTPHost === '')
-		{
-			throw MailerException::forNoHostname();
-		}
-
-		if (! $this->SMTPConnect() || ! $this->SMTPAuthenticate())
-		{
-			return false;
-		}
-
-		if (! $this->sendCommand('from', $this->cleanEmail($this->headers['From'])))
-		{
-			$this->SMTPEnd();
-
-			return false;
-		}
-
-		foreach ($this->recipients as $val)
-		{
-			if (! $this->sendCommand('to', $val))
-			{
-				$this->SMTPEnd();
-
-				return false;
-			}
-		}
-
-		foreach ($this->CCArray as $val)
-		{
-			if ($val !== '' && ! $this->sendCommand('to', $val))
-			{
-				$this->SMTPEnd();
-
-				return false;
-			}
-		}
-
-		foreach ($this->BCCArray as $val)
-		{
-			if ($val !== '' && ! $this->sendCommand('to', $val))
-			{
-				$this->SMTPEnd();
-
-				return false;
-			}
-		}
-
-		if (! $this->sendCommand('data'))
-		{
-			$this->SMTPEnd();
-
-			return false;
-		}
-
-		// perform dot transformation on any lines that begin with a dot
-		$this->sendData($this->headerStr . preg_replace('/^\./m', '..$1', $this->finalBody));
-
-		$this->sendData('.');
-		$reply = $this->getSMTPData();
-		$this->setErrorMessage($reply);
-
-		$this->SMTPEnd();
-
-		if (strpos($reply, '250') !== 0)
-		{
-			throw MailerException::forSMTPError($reply);
-		}
-
-		return true;
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * SMTP End
-	 *
-	 * Shortcut to send RSET or QUIT depending on keep-alive
-	 */
-	protected function SMTPEnd()
-	{
-		$this->sendCommand($this->SMTPKeepAlive ? 'reset' : 'quit');
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * SMTP Connect
-	 *
-	 * @return string
-	 */
-	protected function SMTPConnect()
-	{
-		if (is_resource($this->SMTPConnect))
-		{
-			return true;
-		}
-
-		$ssl = ($this->SMTPCrypto === 'ssl') ? 'ssl://' : '';
-
-		$this->SMTPConnect = fsockopen(
-				$ssl . $this->SMTPHost, $this->SMTPPort, $errno, $errstr, $this->SMTPTimeout
-		);
-
-		if (! is_resource($this->SMTPConnect))
-		{
-			throw MailerException::forSMTPError($errno . ' ' . $errstr);
-		}
-
-		stream_set_timeout($this->SMTPConnect, $this->SMTPTimeout);
-		$this->setErrorMessage($this->getSMTPData());
-
-		if ($this->SMTPCrypto === 'tls')
-		{
-			$this->sendCommand('hello');
-			$this->sendCommand('starttls');
-
-			$crypto = stream_socket_enable_crypto($this->SMTPConnect, true, STREAM_CRYPTO_METHOD_TLS_CLIENT);
-
-			if ($crypto !== true)
-			{
-				throw MailerException::forSMTPError($this->getSMTPData());
-			}
-		}
-
-		return $this->sendCommand('hello');
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Send SMTP command
-	 *
-	 * @param string $cmd
-	 * @param string $data
-	 *
-	 * @return boolean
-	 */
-	protected function sendCommand($cmd, $data = '')
-	{
-		switch ($cmd)
-		{
-			case 'hello':
-				if ($this->SMTPAuth || $this->getEncoding() === '8bit')
-				{
-					$this->sendData('EHLO ' . $this->getHostname());
-				}
-				else
-				{
-					$this->sendData('HELO ' . $this->getHostname());
-				}
-
-				$resp = 250;
-				break;
-			case 'starttls':
-				$this->sendData('STARTTLS');
-				$resp = 220;
-				break;
-			case 'from':
-				$this->sendData('MAIL FROM:<' . $data . '>');
-				$resp = 250;
-				break;
-			case 'to':
-				if ($this->DSN)
-				{
-					$this->sendData('RCPT TO:<' . $data . '> NOTIFY=SUCCESS,DELAY,FAILURE ORCPT=rfc822;' . $data);
-				}
-				else
-				{
-					$this->sendData('RCPT TO:<' . $data . '>');
-				}
-				$resp = 250;
-				break;
-			case 'data':
-				$this->sendData('DATA');
-				$resp = 354;
-				break;
-			case 'reset':
-				$this->sendData('RSET');
-				$resp = 250;
-				break;
-			case 'quit':
-				$this->sendData('QUIT');
-				$resp = 221;
-				break;
-		}
-
-		$reply = $this->getSMTPData();
-
-		$this->debugMessage[] = '<pre>' . $cmd . ': ' . $reply . '</pre>';
-
-		if ((int) static::substr($reply, 0, 3) !== $resp)
-		{
-			throw MailerException::forSMTPError($reply);
-		}
-
-		if ($cmd === 'quit')
-		{
-			fclose($this->SMTPConnect);
-		}
-
-		return true;
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * SMTP Authenticate
-	 *
-	 * @return boolean
-	 */
-	protected function SMTPAuthenticate()
-	{
-		if (! $this->SMTPAuth)
-		{
-			return true;
-		}
-
-		if ($this->SMTPUser === '' && $this->SMTPPass === '')
-		{
-			throw MailerException::forNoSMTPAuth();
-		}
-
-		$this->sendData('AUTH LOGIN');
-		$reply = $this->getSMTPData();
-
-		if (strpos($reply, '503') === 0)    // Already authenticated
-		{
-			return true;
-		}
-		elseif (strpos($reply, '334') !== 0)
-		{
-			throw MailerException::forFailedSMTPLogin($reply);
-		}
-
-		$this->sendData(base64_encode($this->SMTPUser));
-		$reply = $this->getSMTPData();
-
-		if (strpos($reply, '334') !== 0)
-		{
-			throw MailerException::forSMTPAuthUsername($reply);
-		}
-
-		$this->sendData(base64_encode($this->SMTPPass));
-		$reply = $this->getSMTPData();
-
-		if (strpos($reply, '235') !== 0)
-		{
-			throw MailerException::forSMTPAuthPassword($reply);
-		}
-
-		if ($this->SMTPKeepAlive)
-		{
-			$this->SMTPAuth = false;
-		}
-
-		return true;
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Send SMTP data
-	 *
-	 * @param string $data
-	 *
-	 * @return boolean
-	 */
-	protected function sendData($data)
-	{
-		$data .= $this->newline;
-		for ($written = $timestamp = 0, $length = static::strlen($data); $written < $length; $written += $result)
-		{
-			if (($result = fwrite($this->SMTPConnect, static::substr($data, $written))) === false)
-			{
-				break;
-			}
-			// See https://bugs.php.net/bug.php?id=39598 and http://php.net/manual/en/function.fwrite.php#96951
-			elseif ($result === 0)
-			{
-				if ($timestamp === 0)
-				{
-					$timestamp = time();
-				}
-				elseif ($timestamp < (time() - $this->SMTPTimeout))
-				{
-					$result = false;
-					break;
-				}
-
-				usleep(250000);
-				continue;
-			}
-			else
-			{
-				$timestamp = 0;
-			}
-		}
-
-		if ($result === false)
-		{
-			throw MailerException::forSMTPDataFailure($data);
-		}
-
-		return true;
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Get SMTP data
-	 *
-	 * @return string
-	 */
-	protected function getSMTPData()
-	{
-		$data = '';
-
-		while ($str = fgets($this->SMTPConnect, 512))
-		{
-			$data .= $str;
-
-			if ($str[3] === ' ')
-			{
-				break;
-			}
-		}
-
-		return $data;
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Get Hostname
-	 *
-	 * There are only two legal types of hostname - either a fully
-	 * qualified domain name (eg: "mail.example.com") or an IP literal
-	 * (eg: "[1.2.3.4]").
-	 *
-	 * @link https://tools.ietf.org/html/rfc5321#section-2.3.5
-	 * @link http://cbl.abuseat.org/namingproblems.html
-	 *
-	 * @return string
-	 */
-	protected function getHostname()
-	{
-		if (isset($_SERVER['SERVER_NAME']))
-		{
-			return $_SERVER['SERVER_NAME'];
-		}
-
-		return isset($_SERVER['SERVER_ADDR']) ? '[' . $_SERVER['SERVER_ADDR'] . ']' : '[127.0.0.1]';
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Get Debug Message
-	 *
-	 * @param array $include List of raw data chunks to include in the output
-	 *                       Valid options are: 'headers', 'subject', 'body'
-	 *
-	 * @return string
-	 */
-	public function printDebugger($include = ['headers', 'subject', 'body'])
-	{
-		$msg = implode('', $this->debugMessage);
-
-		// Determine which parts of our raw data needs to be printed
-		$raw_data                      = '';
-		is_array($include) || $include = [$include];
-
-		in_array('headers', $include, true) && $raw_data  = htmlspecialchars($this->headerStr) . "\n";
-		in_array('subject', $include, true) && $raw_data .= htmlspecialchars($this->subject) . "\n";
-		in_array('body', $include, true) && $raw_data    .= htmlspecialchars($this->finalBody);
-
-		return $msg . ($raw_data === '' ? '' : '<pre>' . $raw_data . '</pre>');
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Set Message
-	 *
-	 * @param string $msg
-	 */
-	protected function setErrorMessage($msg)
-	{
-		$this->debugMessage[] = $msg . '<br />';
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Mime Types
-	 *
-	 * @param string $ext
-	 *
-	 * @return string
-	 */
-	protected function mimeTypes($ext = '')
-	{
-		$mime = Mimes::guessTypeFromExtension(strtolower($ext));
-
-		return ! empty($mime) ? $mime : 'application/x-unknown-content-type';
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Destructor
-	 */
-	public function __destruct()
-	{
-		is_resource($this->SMTPConnect) && $this->sendCommand('quit');
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Byte-safe strlen()
-	 *
-	 * @param string $str
-	 *
-	 * @return integer
-	 */
-	protected static function strlen($str)
-	{
-		return (static::$func_overload) ? mb_strlen($str, '8bit') : strlen($str);
-	}
-
-	//--------------------------------------------------------------------
-
-	/**
-	 * Byte-safe substr()
-	 *
-	 * @param string       $str
-	 * @param integer      $start
-	 * @param integer|null $length
-	 *
-	 * @return string
-	 */
-	protected static function substr($str, $start, $length = null)
-	{
-		if (static::$func_overload)
-		{
-			return mb_substr($str, $start, $length, '8bit');
-		}
-
-		return isset($length) ? substr($str, $start, $length) : substr($str, $start);
-	}
-
+    /**
+     * Message format.
+     *
+     * @var string 'text' or 'html'
+     */
+    public $mailType = 'text';
+
+    /**
+     * Character set (default: utf-8)
+     *
+     * @var string
+     */
+    public $charset = 'utf-8';
+
+    /**
+     * Alternative message (for HTML messages only)
+     *
+     * @var string
+     */
+    public $altMessage = '';
+
+    /**
+     * Whether to validate email addresses.
+     *
+     * @var bool
+     */
+    public $validate = true;
+
+    /**
+     * X-Priority header value.
+     *
+     * @var int 1-5
+     */
+    public $priority = 3;            // Default priority (1 - 5)
+
+    /**
+     * Newline character sequence.
+     * Use "\r\n" to comply with RFC 822.
+     *
+     * @see http://www.ietf.org/rfc/rfc822.txt
+     *
+     * @var string "\r\n" or "\n"
+     */
+    public $newline = "\n";            // Default newline. "\r\n" or "\n" (Use "\r\n" to comply with RFC 822)
+
+    /**
+     * CRLF character sequence
+     *
+     * RFC 2045 specifies that for 'quoted-printable' encoding,
+     * "\r\n" must be used. However, it appears that some servers
+     * (even on the receiving end) don't handle it properly and
+     * switching to "\n", while improper, is the only solution
+     * that seems to work for all environments.
+     *
+     * @see http://www.ietf.org/rfc/rfc822.txt
+     *
+     * @var string
+     */
+    public $CRLF = "\n";
+
+    /**
+     * Whether to use Delivery Status Notification.
+     *
+     * @var bool
+     */
+    public $DSN = false;
+
+    /**
+     * Whether to send multipart alternatives.
+     * Yahoo! doesn't seem to like these.
+     *
+     * @var bool
+     */
+    public $sendMultipart = true;
+
+    /**
+     * Whether to send messages to BCC recipients in batches.
+     *
+     * @var bool
+     */
+    public $BCCBatchMode = false;
+
+    /**
+     * BCC Batch max number size.
+     *
+     * @see Mailer::$BCCBatchMode
+     *
+     * @var int
+     */
+    public $BCCBatchSize = 200;
+
+    /**
+     * Subject header
+     *
+     * @var string
+     */
+    protected $subject = '';
+
+    /**
+     * Message body
+     *
+     * @var string
+     */
+    protected $body = '';
+
+    /**
+     * Final message body to be sent.
+     *
+     * @var string
+     */
+    protected $finalBody = '';
+
+    /**
+     * Final headers to send
+     *
+     * @var string
+     */
+    protected $headerStr = '';
+
+    /**
+     * SMTP Connection socket placeholder
+     *
+     * @var resource
+     */
+    protected $SMTPConnect = '';
+
+    /**
+     * Mail encoding
+     *
+     * @var string '8bit' or '7bit'
+     */
+    protected $encoding = '8bit';
+
+    /**
+     * Whether to send a Reply-To header
+     *
+     * @var bool
+     */
+    protected $replyToFlag = false;
+
+    /**
+     * Debug messages
+     *
+     * @see Mailer::printDebugger()
+     *
+     * @var array
+     */
+    protected $debugMessage = [];
+
+    /**
+     * Recipients
+     *
+     * @var array
+     */
+    protected $recipients = [];
+
+    /**
+     * CC Recipients
+     *
+     * @var array
+     */
+    protected $CCArray = [];
+
+    /**
+     * BCC Recipients
+     *
+     * @var array
+     */
+    protected $BCCArray = [];
+
+    /**
+     * Message headers
+     *
+     * @var array
+     */
+    protected $headers = [];
+
+    /**
+     * Attachment data
+     *
+     * @var array
+     */
+    protected $attachments = [];
+
+    /**
+     * Valid $protocol values
+     *
+     * @see Mailer::$protocol
+     *
+     * @var array
+     */
+    protected $protocols = [
+        'mail',
+        'sendmail',
+        'smtp',
+    ];
+
+    /**
+     * Base charsets
+     *
+     * Character sets valid for 7-bit encoding,
+     * excluding language suffix.
+     *
+     * @var array
+     */
+    protected $baseCharsets = [
+        'us-ascii',
+        'iso-2022-',
+    ];
+
+    /**
+     * Bit depths
+     *
+     * Valid mail encodings
+     *
+     * @see Mailer::$encoding
+     *
+     * @var array
+     */
+    protected $bitDepths = [
+        '7bit',
+        '8bit',
+    ];
+
+    /**
+     * $priority translations
+     *
+     * Actual values to send with the X-Priority header
+     *
+     * @var array
+     */
+    protected $priorities = [
+        1 => '1 (Highest)',
+        2 => '2 (High)',
+        3 => '3 (Normal)',
+        4 => '4 (Low)',
+        5 => '5 (Lowest)',
+    ];
+
+    /**
+     * mbstring.func_overload flag
+     *
+     * @var bool
+     */
+    protected static $func_overload;
+
+    /**
+     * Logger instance to record error messages and awarnings.
+     *
+     * @var \PSR\Log\LoggerInterface
+     */
+    protected $logger;
+
+    /**
+     * Constructor - Sets Mailer Preferences
+     *
+     * The constructor can be passed an array of config values
+     *
+     * @param array|null $config
+     */
+    public function __construct($config = null)
+    {
+        $this->protocol = 'smtp';
+        $this->initialize($config);
+
+        log_message('info', 'Mailer Class Initialized');
+    }
+
+    /**
+     * Initialize preferences
+     *
+     * @param array|\Config\Mailer $config
+     *
+     * @return Mailer
+     */
+    public function initialize($config)
+    {
+        $this->clear();
+
+        if ($config instanceof \Config\Mailer) {
+            $config = get_object_vars($config);
+        }
+
+        foreach (get_class_vars(static::class) as $key => $value) {
+            if (property_exists($this, $key) && isset($config[$key])) {
+                $method = 'set' . ucfirst($key);
+
+                if (method_exists($this, $method)) {
+                    $this->{$method}($config[$key]);
+                } else {
+                    $this->{$key} = $config[$key];
+                }
+            }
+        }
+
+        $this->charset  = strtoupper($this->charset);
+        $this->SMTPAuth = isset($this->SMTPUser[0], $this->SMTPPass[0]);
+
+        return $this;
+    }
+
+    /**
+     * Initialize the Mailer Data
+     *
+     * @param bool $clearAttachments
+     *
+     * @return Mailer
+     */
+    public function clear($clearAttachments = false)
+    {
+        $this->subject      = '';
+        $this->body         = '';
+        $this->finalBody    = '';
+        $this->headerStr    = '';
+        $this->replyToFlag  = false;
+        $this->recipients   = [];
+        $this->CCArray      = [];
+        $this->BCCArray     = [];
+        $this->headers      = [];
+        $this->debugMessage = [];
+
+        //      $this->setHeader('Date', $this->setDate());
+
+        if ($clearAttachments !== false) {
+            $this->attachments = [];
+        }
+
+        return $this;
+    }
+
+    /**
+     * Build final headers
+     */
+    protected function buildHeaders()
+    {
+        $this->setHeader('User-Agent', $this->userAgent);
+        $this->setHeader('X-Sender', $this->cleanEmail($this->headers['From']));
+        $this->setHeader('X-Mailer', $this->userAgent);
+        $this->setHeader('X-Priority', $this->priorities[$this->priority]);
+        $this->setHeader('Message-ID', $this->getMessageID());
+        $this->setHeader('Mime-Version', '1.0');
+    }
+
+    /**
+     * Write Headers as a string
+     */
+    protected function writeHeaders()
+    {
+        if ($this->protocol === 'mail') {
+            if (isset($this->headers['Subject'])) {
+                $this->subject = $this->headers['Subject'];
+                unset($this->headers['Subject']);
+            }
+        }
+
+        reset($this->headers);
+        $this->headerStr = '';
+
+        foreach ($this->headers as $key => $val) {
+            $val = trim($val);
+
+            if ($val !== '') {
+                $this->headerStr .= $key . ': ' . $val . $this->newline;
+            }
+        }
+
+        if ($this->getProtocol() === 'mail') {
+            $this->headerStr = rtrim($this->headerStr);
+        }
+    }
+
+    /**
+     * Build Final Body and attachments
+     */
+    protected function buildMessage()
+    {
+        if ($this->wordWrap === true && $this->mailType !== 'html') {
+            $this->body = $this->wordWrap($this->body);
+        }
+
+        $this->writeHeaders();
+
+        $hdr  = ($this->getProtocol() === 'mail') ? $this->newline : '';
+        $body = '';
+
+        switch ($this->getContentType()) {
+            case 'plain':
+
+                $hdr .= 'Content-Type: text/plain; charset=' . $this->charset . $this->newline
+                        . 'Content-Transfer-Encoding: ' . $this->getEncoding();
+
+                if ($this->getProtocol() === 'mail') {
+                    $this->headerStr .= $hdr;
+                    $this->finalBody = $this->body;
+                } else {
+                    $this->finalBody = $hdr . $this->newline . $this->newline . $this->body;
+                }
+
+                return;
+
+            case 'html':
+
+                if ($this->sendMultipart === false) {
+                    $hdr .= 'Content-Type: text/html; charset=' . $this->charset . $this->newline
+                            . 'Content-Transfer-Encoding: quoted-printable';
+                } else {
+                    $boundary = uniqid('B_ALT_', true);
+                    $hdr .= 'Content-Type: multipart/alternative; boundary="' . $boundary . '"';
+
+                    $body .= $this->getMimeMessage() . $this->newline . $this->newline
+                            . '--' . $boundary . $this->newline
+                            . 'Content-Type: text/plain; charset=' . $this->charset . $this->newline
+                            . 'Content-Transfer-Encoding: ' . $this->getEncoding() . $this->newline . $this->newline
+                            . $this->getAltMessage() . $this->newline . $this->newline
+                            . '--' . $boundary . $this->newline
+                            . 'Content-Type: text/html; charset=' . $this->charset . $this->newline
+                            . 'Content-Transfer-Encoding: quoted-printable' . $this->newline . $this->newline;
+                }
+
+                $this->finalBody = $body . $this->prepQuotedPrintable($this->body) . $this->newline . $this->newline;
+
+                if ($this->getProtocol() === 'mail') {
+                    $this->headerStr .= $hdr;
+                } else {
+                    $this->finalBody = $hdr . $this->newline . $this->newline . $this->finalBody;
+                }
+
+                if ($this->sendMultipart !== false) {
+                    $this->finalBody .= '--' . $boundary . '--';
+                }
+
+                return;
+
+            case 'plain-attach':
+
+                $boundary = uniqid('B_ATC_', true);
+                $hdr .= 'Content-Type: multipart/mixed; boundary="' . $boundary . '"';
+
+                if ($this->getProtocol() === 'mail') {
+                    $this->headerStr .= $hdr;
+                }
+
+                $body .= $this->getMimeMessage() . $this->newline
+                        . $this->newline
+                        . '--' . $boundary . $this->newline
+                        . 'Content-Type: text/plain; charset=' . $this->charset . $this->newline
+                        . 'Content-Transfer-Encoding: ' . $this->getEncoding() . $this->newline
+                        . $this->newline
+                        . $this->body . $this->newline . $this->newline;
+
+                $this->appendAttachments($body, $boundary);
+
+                break;
+
+            case 'html-attach':
+
+                $alt_boundary  = uniqid('B_ALT_', true);
+                $last_boundary = null;
+
+                if ($this->attachmentsHaveMultipart('mixed')) {
+                    $atc_boundary = uniqid('B_ATC_', true);
+                    $hdr .= 'Content-Type: multipart/mixed; boundary="' . $atc_boundary . '"';
+                    $last_boundary = $atc_boundary;
+                }
+
+                if ($this->attachmentsHaveMultipart('related')) {
+                    $rel_boundary        = uniqid('B_REL_', true);
+                    $rel_boundary_header = 'Content-Type: multipart/related; boundary="' . $rel_boundary . '"';
+
+                    if (isset($last_boundary)) {
+                        $body .= '--' . $last_boundary . $this->newline . $rel_boundary_header;
+                    } else {
+                        $hdr .= $rel_boundary_header;
+                    }
+
+                    $last_boundary = $rel_boundary;
+                }
+
+                if ($this->getProtocol() === 'mail') {
+                    $this->headerStr .= $hdr;
+                }
+
+                static::strlen($body) && $body .= $this->newline . $this->newline;
+                $body                          .= $this->getMimeMessage() . $this->newline . $this->newline
+                        . '--' . $last_boundary . $this->newline
+                        . 'Content-Type: multipart/alternative; boundary="' . $alt_boundary . '"' . $this->newline . $this->newline
+                        . '--' . $alt_boundary . $this->newline
+                        . 'Content-Type: text/plain; charset=' . $this->charset . $this->newline
+                        . 'Content-Transfer-Encoding: ' . $this->getEncoding() . $this->newline . $this->newline
+                        . $this->getAltMessage() . $this->newline . $this->newline
+                        . '--' . $alt_boundary . $this->newline
+                        . 'Content-Type: text/html; charset=' . $this->charset . $this->newline
+                        . 'Content-Transfer-Encoding: quoted-printable' . $this->newline . $this->newline
+                        . $this->prepQuotedPrintable($this->body) . $this->newline . $this->newline
+                        . '--' . $alt_boundary . '--' . $this->newline . $this->newline;
+
+                if (! empty($rel_boundary)) {
+                    $body .= $this->newline . $this->newline;
+                    $this->appendAttachments($body, $rel_boundary, 'related');
+                }
+
+                // multipart/mixed attachments
+                if (! empty($atc_boundary)) {
+                    $body .= $this->newline . $this->newline;
+                    $this->appendAttachments($body, $atc_boundary, 'mixed');
+                }
+
+                break;
+        }
+
+        $this->finalBody = ($this->getProtocol() === 'mail') ? $body : $hdr . $this->newline . $this->newline . $body;
+    }
+
+    /**
+     * Prepares attachment string
+     *
+     * @param string      &$body     Message body to append to
+     * @param string      $boundary  Multipart boundary
+     * @param string|null $multipart When provided, only attachments of this type will be processed
+     *
+     * @return string
+     */
+    protected function appendAttachments(&$body, $boundary, $multipart = null)
+    {
+        for ($i = 0, $c = count($this->attachments); $i < $c; $i++) {
+            if (isset($multipart) && $this->attachments[$i]['multipart'] !== $multipart) {
+                continue;
+            }
+
+            $name = $this->attachments[$i]['name'][1] ?? basename($this->attachments[$i]['name'][0]);
+
+            $body .= '--' . $boundary . $this->newline
+                    . 'Content-Type: ' . $this->attachments[$i]['type'] . '; name="' . $name . '"' . $this->newline
+                    . 'Content-Disposition: ' . $this->attachments[$i]['disposition'] . ';' . $this->newline
+                    . 'Content-Transfer-Encoding: base64' . $this->newline
+                    . (empty($this->attachments[$i]['cid']) ? '' : 'Content-ID: <' . $this->attachments[$i]['cid'] . '>' . $this->newline)
+                    . $this->newline
+                    . $this->attachments[$i]['content'] . $this->newline;
+        }
+
+        // $name won't be set if no attachments were appended,
+        // and therefore a boundary wouldn't be necessary
+        empty($name) || $body .= '--' . $boundary . '--';
+    }
+
+    /**
+     * Prep Quoted Printable
+     *
+     * Prepares string for Quoted-Printable Content-Transfer-Encoding
+     * Refer to RFC 2045 http://www.ietf.org/rfc/rfc2045.txt
+     *
+     * @param string $str
+     *
+     * @return string
+     */
+    protected function prepQuotedPrintable($str)
+    {
+        // ASCII code numbers for "safe" characters that can always be
+        // used literally, without encoding, as described in RFC 2049.
+        // http://www.ietf.org/rfc/rfc2049.txt
+        static $ascii_safe_chars = [
+            // ' (  )   +   ,   -   .   /   :   =   ?
+            39,
+            40,
+            41,
+            43,
+            44,
+            45,
+            46,
+            47,
+            58,
+            61,
+            63,
+            // numbers
+            48,
+            49,
+            50,
+            51,
+            52,
+            53,
+            54,
+            55,
+            56,
+            57,
+            // upper-case letters
+            65,
+            66,
+            67,
+            68,
+            69,
+            70,
+            71,
+            72,
+            73,
+            74,
+            75,
+            76,
+            77,
+            78,
+            79,
+            80,
+            81,
+            82,
+            83,
+            84,
+            85,
+            86,
+            87,
+            88,
+            89,
+            90,
+            // lower-case letters
+            97,
+            98,
+            99,
+            100,
+            101,
+            102,
+            103,
+            104,
+            105,
+            106,
+            107,
+            108,
+            109,
+            110,
+            111,
+            112,
+            113,
+            114,
+            115,
+            116,
+            117,
+            118,
+            119,
+            120,
+            121,
+            122,
+        ];
+
+        // We are intentionally wrapping so mail servers will encode characters
+        // properly and MUAs will behave, so {unwrap} must go!
+        $str = str_replace(['{unwrap}', '{/unwrap}'], '', $str);
+
+        // RFC 2045 specifies CRLF as "\r\n".
+        // However, many developers choose to override that and violate
+        // the RFC rules due to (apparently) a bug in MS Exchange,
+        // which only works with "\n".
+        if ($this->CRLF === "\r\n") {
+            return quoted_printable_encode($str);
+        }
+
+        // Reduce multiple spaces & remove nulls
+        $str = preg_replace(['| +|', '/\x00+/'], [' ', ''], $str);
+
+        // Standardize newlines
+        if (strpos($str, "\r") !== false) {
+            $str = str_replace(["\r\n", "\r"], "\n", $str);
+        }
+
+        $escape = '=';
+        $output = '';
+
+        foreach (explode("\n", $str) as $line) {
+            $length = static::strlen($line);
+            $temp   = '';
+
+            // Loop through each character in the line to add soft-wrap
+            // characters at the end of a line " =\r\n" and add the newly
+            // processed line(s) to the output (see comment on $crlf class property)
+            for ($i = 0; $i < $length; $i++) {
+                // Grab the next character
+                $char  = $line[$i];
+                $ascii = ord($char);
+
+                // Convert spaces and tabs but only if it's the end of the line
+                if ($ascii === 32 || $ascii === 9) {
+                    if ($i === ($length - 1)) {
+                        $char = $escape . sprintf('%02s', dechex($ascii));
+                    }
+                }
+                // DO NOT move this below the $ascii_safe_chars line!
+                //
+                // = (equals) signs are allowed by RFC2049, but must be encoded
+                // as they are the encoding delimiter!
+                elseif ($ascii === 61) {
+                    $char = $escape . strtoupper(sprintf('%02s', dechex($ascii)));  // =3D
+                } elseif (! in_array($ascii, $ascii_safe_chars, true)) {
+                    $char = $escape . strtoupper(sprintf('%02s', dechex($ascii)));
+                }
+
+                // If we're at the character limit, add the line to the output,
+                // reset our temp variable, and keep on chuggin'
+                if ((static::strlen($temp) + static::strlen($char)) >= 76) {
+                    $output .= $temp . $escape . $this->CRLF;
+                    $temp = '';
+                }
+
+                // Add the character to our temporary line
+                $temp .= $char;
+            }
+
+            // Add our completed line to the output
+            $output .= $temp . $this->CRLF;
+        }
+
+        // get rid of extra CRLF tacked onto the end
+        return static::substr($output, 0, static::strlen($this->CRLF) * -1);
+    }
+
+    /**
+     * Prep Q Encoding
+     *
+     * Performs "Q Encoding" on a string for use in email headers.
+     * It's related but not identical to quoted-printable, so it has its
+     * own method.
+     *
+     * @param string $str
+     *
+     * @return string
+     */
+    protected function prepQEncoding($str)
+    {
+        $str = str_replace(["\r", "\n"], '', $str);
+
+        if ($this->charset === 'UTF-8') {
+            // Note: We used to have mb_encode_mimeheader() as the first choice
+            // here, but it turned out to be buggy and unreliable. DO NOT
+            //       re-add it! -- Narf
+            if (extension_loaded('iconv')) {
+                $output = @iconv_mime_encode(
+                    '',
+                    $str,
+                    [
+                        'scheme'           => 'Q',
+                        'line-length'      => 76,
+                        'input-charset'    => $this->charset,
+                        'output-charset'   => $this->charset,
+                        'line-break-chars' => $this->CRLF,
+                    ]
+                );
+
+                // There are reports that iconv_mime_encode() might fail and return FALSE
+                if ($output !== false) {
+                    // iconv_mime_encode() will always put a header field name.
+                    // We've passed it an empty one, but it still prepends our
+                    // encoded string with ': ', so we need to strip it.
+                    return static::substr($output, 2);
+                }
+
+                $chars = iconv_strlen($str, 'UTF-8');
+            } elseif (extension_loaded('mbstring')) {
+                $chars = mb_strlen($str, 'UTF-8');
+            }
+        }
+
+        // We might already have this set for UTF-8
+        isset($chars) || $chars = static::strlen($str);
+
+        $output = '=?' . $this->charset . '?Q?';
+
+        for ($i = 0, $length = static::strlen($output); $i < $chars; $i++) {
+            $chr = ($this->charset === 'UTF-8' && ICONV_ENABLED === true) ? '=' . implode('=', str_split(strtoupper(bin2hex(iconv_substr($str, $i, 1, $this->charset))), 2)) : '=' . strtoupper(bin2hex($str[$i]));
+
+            // RFC 2045 sets a limit of 76 characters per line.
+            // We'll append ?= to the end of each line though.
+            if ($length + ($l = static::strlen($chr)) > 74) {
+                $output .= '?=' . $this->CRLF // EOL
+                        . ' =?' . $this->charset . '?Q?' . $chr; // New line
+                $length = 6 + static::strlen($this->charset) + $l; // Reset the length for the new line
+            } else {
+                $output .= $chr;
+                $length += $l;
+            }
+        }
+
+        // End the header
+        return $output . '?=';
+    }
+
+    /**
+     * Send the Message
+     *
+     * @return bool
+     */
+    public function send(Email $email)
+    {
+        if (! isset($this->headers['From']) && ! empty($this->fromEmail)) {
+            $this->setFrom($this->fromEmail, $this->fromName);
+        }
+
+        if (! isset($this->headers['From'])) {
+            throw MailerException::forNoFrom();
+        }
+
+        if ($this->replyToFlag === false) {
+            $this->setReplyTo($this->headers['From']);
+        }
+
+        if (empty($this->recipients) && ! isset($this->headers['To']) && empty($this->BCCArray) && ! isset($this->headers['Bcc']) && ! isset($this->headers['Cc'])
+        ) {
+            throw MailerException::forNoRecipients();
+        }
+
+        $this->buildHeaders();
+
+        if ($this->BCCBatchMode && count($this->BCCArray) > $this->BCCBatchSize) {
+            $this->batchBCCSend();
+
+            if ($autoClear) {
+                $this->clear();
+            }
+
+            return true;
+        }
+
+        $this->buildMessage();
+        $result = $this->spoolEmail();
+
+        if ($result && $autoClear) {
+            $this->clear();
+        }
+
+        return $result;
+    }
+
+    /**
+     * Batch Bcc Send. Sends groups of BCCs in batches
+     */
+    public function batchBCCSend()
+    {
+        $float = $this->BCCBatchSize - 1;
+        $set   = '';
+        $chunk = [];
+
+        for ($i = 0, $c = count($this->BCCArray); $i < $c; $i++) {
+            if (isset($this->BCCArray[$i])) {
+                $set .= ', ' . $this->BCCArray[$i];
+            }
+
+            if ($i === $float) {
+                $chunk[] = static::substr($set, 1);
+                $float += $this->BCCBatchSize;
+                $set = '';
+            }
+
+            if ($i === $c - 1) {
+                $chunk[] = static::substr($set, 1);
+            }
+        }
+
+        for ($i = 0, $c = count($chunk); $i < $c; $i++) {
+            unset($this->headers['Bcc']);
+
+            $bcc = $this->cleanEmail($this->stringToArray($chunk[$i]));
+
+            if ($this->protocol !== 'smtp') {
+                $this->setHeader('Bcc', implode(', ', $bcc));
+            } else {
+                $this->BCCArray = $bcc;
+            }
+
+            $this->buildMessage();
+            $this->spoolEmail();
+        }
+    }
+
+    /**
+     * Unwrap special elements
+     */
+    protected function unwrapSpecials()
+    {
+        $this->finalBody = preg_replace_callback(
+            '/\{unwrap\}(.*?)\{\/unwrap\}/si',
+            [
+                $this,
+                'removeNLCallback',
+            ],
+            $this->finalBody
+        );
+    }
+
+    /**
+     * Strip line-breaks via callback
+     *
+     * @param string $matches
+     *
+     * @return string
+     */
+    protected function removeNLCallback($matches)
+    {
+        if (strpos($matches[1], "\r") !== false || strpos($matches[1], "\n") !== false) {
+            $matches[1] = str_replace(["\r\n", "\r", "\n"], '', $matches[1]);
+        }
+
+        return $matches[1];
+    }
+
+    /**
+     * Spool mail to the mail server
+     *
+     * @return bool
+     */
+    protected function spoolEmail()
+    {
+        $this->unwrapSpecials();
+
+        $protocol = $this->getProtocol();
+        $method   = 'sendWith' . ucfirst($protocol);
+
+        try {
+            $success = $this->{$method}();
+        } catch (ErrorException $e) {
+            $success = false;
+            $this->logger->error('Mailer: ' . $method . ' throwed ' . $e->getMessage());
+        }
+
+        if (! $success) {
+            throw MailerException::forSendFailure($protocol === 'mail' ? 'PHPMail' : ucfirst($protocol));
+        }
+
+        $this->setErrorMessage(lang('Mailer.sent', [$protocol]));
+
+        return true;
+    }
+
+    /**
+     * Validate email for shell
+     *
+     * Applies stricter, shell-safe validation to email addresses.
+     * Introduced to prevent RCE via sendmail's -f option.
+     *
+     * @see     https://github.com/codeigniter4/CodeIgniter/issues/4963
+     * @see     https://gist.github.com/Zenexer/40d02da5e07f151adeaeeaa11af9ab36
+     *
+     * @license https://creativecommons.org/publicdomain/zero/1.0/    CC0 1.0, Public Domain
+     *
+     * Credits for the base concept go to Paul Buonopane <paul@namepros.com>
+     *
+     * @param string &$email
+     *
+     * @return bool
+     */
+    protected function validateEmailForShell(&$email)
+    {
+        if (function_exists('idn_to_ascii') && $atpos = strpos($email, '@')) {
+            $email = static::substr($email, 0, ++$atpos) . idn_to_ascii(
+                static::substr($email, $atpos),
+                0,
+                INTL_IDNA_VARIANT_UTS46
+            );
+        }
+
+        return filter_var($email, FILTER_VALIDATE_EMAIL) === $email && preg_match('#\A[a-z0-9._+-]+@[a-z0-9.-]{1,253}\z#i', $email);
+    }
+
+    /**
+     * Send using mail()
+     *
+     * @return bool
+     */
+    protected function sendWithMail()
+    {
+        if (is_array($this->recipients)) {
+            $this->recipients = implode(', ', $this->recipients);
+        }
+
+        // _validate_email_for_shell() below accepts by reference,
+        // so this needs to be assigned to a variable
+        $from = $this->cleanEmail($this->headers['Return-Path']);
+
+        if (! $this->validateEmailForShell($from)) {
+            return mail($this->recipients, $this->subject, $this->finalBody, $this->headerStr);
+        }
+
+        // most documentation of sendmail using the "-f" flag lacks a space after it, however
+        // we've encountered servers that seem to require it to be in place.
+        return mail($this->recipients, $this->subject, $this->finalBody, $this->headerStr, '-f ' . $from);
+    }
+
+    /**
+     * Send using Sendmail
+     *
+     * @return bool
+     */
+    protected function sendWithSendmail()
+    {
+        // _validate_email_for_shell() below accepts by reference,
+        // so this needs to be assigned to a variable
+        $from = $this->cleanEmail($this->headers['From']);
+        if ($this->validateEmailForShell($from)) {
+            $from = '-f ' . $from;
+        } else {
+            $from = '';
+        }
+
+        // is popen() enabled?
+        if (! function_usable('popen') || false === ($fp = @popen($this->mailPath . ' -oi ' . $from . ' -t', 'w'))) {
+            // server probably has popen disabled, so nothing we can do to get a verbose error.
+            return false;
+        }
+
+        fwrite($fp, $this->headerStr);
+        fwrite($fp, $this->finalBody);
+
+        $status = pclose($fp);
+
+        if ($status !== 0) {
+            throw MailerException::forNosocket($status);
+        }
+
+        return true;
+    }
+
+    /**
+     * Send using SMTP
+     *
+     * @return bool
+     */
+    protected function sendWithSmtp()
+    {
+        if ($this->SMTPHost === '') {
+            throw MailerException::forNoHostname();
+        }
+
+        if (! $this->SMTPConnect() || ! $this->SMTPAuthenticate()) {
+            return false;
+        }
+
+        if (! $this->sendCommand('from', $this->cleanEmail($this->headers['From']))) {
+            $this->SMTPEnd();
+
+            return false;
+        }
+
+        foreach ($this->recipients as $val) {
+            if (! $this->sendCommand('to', $val)) {
+                $this->SMTPEnd();
+
+                return false;
+            }
+        }
+
+        foreach ($this->CCArray as $val) {
+            if ($val !== '' && ! $this->sendCommand('to', $val)) {
+                $this->SMTPEnd();
+
+                return false;
+            }
+        }
+
+        foreach ($this->BCCArray as $val) {
+            if ($val !== '' && ! $this->sendCommand('to', $val)) {
+                $this->SMTPEnd();
+
+                return false;
+            }
+        }
+
+        if (! $this->sendCommand('data')) {
+            $this->SMTPEnd();
+
+            return false;
+        }
+
+        // perform dot transformation on any lines that begin with a dot
+        $this->sendData($this->headerStr . preg_replace('/^\./m', '..$1', $this->finalBody));
+
+        $this->sendData('.');
+        $reply = $this->getSMTPData();
+        $this->setErrorMessage($reply);
+
+        $this->SMTPEnd();
+
+        if (strpos($reply, '250') !== 0) {
+            throw MailerException::forSMTPError($reply);
+        }
+
+        return true;
+    }
+
+    /**
+     * SMTP End
+     *
+     * Shortcut to send RSET or QUIT depending on keep-alive
+     */
+    protected function SMTPEnd()
+    {
+        $this->sendCommand($this->SMTPKeepAlive ? 'reset' : 'quit');
+    }
+
+    /**
+     * SMTP Connect
+     *
+     * @return string
+     */
+    protected function SMTPConnect()
+    {
+        if (is_resource($this->SMTPConnect)) {
+            return true;
+        }
+
+        $ssl = ($this->SMTPCrypto === 'ssl') ? 'ssl://' : '';
+
+        $this->SMTPConnect = fsockopen(
+            $ssl . $this->SMTPHost,
+            $this->SMTPPort,
+            $errno,
+            $errstr,
+            $this->SMTPTimeout
+        );
+
+        if (! is_resource($this->SMTPConnect)) {
+            throw MailerException::forSMTPError($errno . ' ' . $errstr);
+        }
+
+        stream_set_timeout($this->SMTPConnect, $this->SMTPTimeout);
+        $this->setErrorMessage($this->getSMTPData());
+
+        if ($this->SMTPCrypto === 'tls') {
+            $this->sendCommand('hello');
+            $this->sendCommand('starttls');
+
+            $crypto = stream_socket_enable_crypto($this->SMTPConnect, true, STREAM_CRYPTO_METHOD_TLS_CLIENT);
+
+            if ($crypto !== true) {
+                throw MailerException::forSMTPError($this->getSMTPData());
+            }
+        }
+
+        return $this->sendCommand('hello');
+    }
+
+    /**
+     * Send SMTP command
+     *
+     * @param string $cmd
+     * @param string $data
+     *
+     * @return bool
+     */
+    protected function sendCommand($cmd, $data = '')
+    {
+        switch ($cmd) {
+            case 'hello':
+                if ($this->SMTPAuth || $this->getEncoding() === '8bit') {
+                    $this->sendData('EHLO ' . $this->getHostname());
+                } else {
+                    $this->sendData('HELO ' . $this->getHostname());
+                }
+
+                $resp = 250;
+                break;
+
+            case 'starttls':
+                $this->sendData('STARTTLS');
+                $resp = 220;
+                break;
+
+            case 'from':
+                $this->sendData('MAIL FROM:<' . $data . '>');
+                $resp = 250;
+                break;
+
+            case 'to':
+                if ($this->DSN) {
+                    $this->sendData('RCPT TO:<' . $data . '> NOTIFY=SUCCESS,DELAY,FAILURE ORCPT=rfc822;' . $data);
+                } else {
+                    $this->sendData('RCPT TO:<' . $data . '>');
+                }
+                $resp = 250;
+                break;
+
+            case 'data':
+                $this->sendData('DATA');
+                $resp = 354;
+                break;
+
+            case 'reset':
+                $this->sendData('RSET');
+                $resp = 250;
+                break;
+
+            case 'quit':
+                $this->sendData('QUIT');
+                $resp = 221;
+                break;
+        }
+
+        $reply = $this->getSMTPData();
+
+        $this->debugMessage[] = '<pre>' . $cmd . ': ' . $reply . '</pre>';
+
+        if ((int) static::substr($reply, 0, 3) !== $resp) {
+            throw MailerException::forSMTPError($reply);
+        }
+
+        if ($cmd === 'quit') {
+            fclose($this->SMTPConnect);
+        }
+
+        return true;
+    }
+
+    /**
+     * SMTP Authenticate
+     *
+     * @return bool
+     */
+    protected function SMTPAuthenticate()
+    {
+        if (! $this->SMTPAuth) {
+            return true;
+        }
+
+        if ($this->SMTPUser === '' && $this->SMTPPass === '') {
+            throw MailerException::forNoSMTPAuth();
+        }
+
+        $this->sendData('AUTH LOGIN');
+        $reply = $this->getSMTPData();
+
+        if (strpos($reply, '503') === 0) {    // Already authenticated
+            return true;
+        }
+        if (strpos($reply, '334') !== 0) {
+            throw MailerException::forFailedSMTPLogin($reply);
+        }
+
+        $this->sendData(base64_encode($this->SMTPUser));
+        $reply = $this->getSMTPData();
+
+        if (strpos($reply, '334') !== 0) {
+            throw MailerException::forSMTPAuthUsername($reply);
+        }
+
+        $this->sendData(base64_encode($this->SMTPPass));
+        $reply = $this->getSMTPData();
+
+        if (strpos($reply, '235') !== 0) {
+            throw MailerException::forSMTPAuthPassword($reply);
+        }
+
+        if ($this->SMTPKeepAlive) {
+            $this->SMTPAuth = false;
+        }
+
+        return true;
+    }
+
+    /**
+     * Send SMTP data
+     *
+     * @param string $data
+     *
+     * @return bool
+     */
+    protected function sendData($data)
+    {
+        $data .= $this->newline;
+
+        for ($written = $timestamp = 0, $length = static::strlen($data); $written < $length; $written += $result) {
+            if (($result = fwrite($this->SMTPConnect, static::substr($data, $written))) === false) {
+                break;
+            }
+            // See https://bugs.php.net/bug.php?id=39598 and http://php.net/manual/en/function.fwrite.php#96951
+            if ($result === 0) {
+                if ($timestamp === 0) {
+                    $timestamp = time();
+                } elseif ($timestamp < (time() - $this->SMTPTimeout)) {
+                    $result = false;
+                    break;
+                }
+
+                usleep(250000);
+
+                continue;
+            }
+
+            $timestamp = 0;
+        }
+
+        if ($result === false) {
+            throw MailerException::forSMTPDataFailure($data);
+        }
+
+        return true;
+    }
+
+    /**
+     * Get SMTP data
+     *
+     * @return string
+     */
+    protected function getSMTPData()
+    {
+        $data = '';
+
+        while ($str = fgets($this->SMTPConnect, 512)) {
+            $data .= $str;
+
+            if ($str[3] === ' ') {
+                break;
+            }
+        }
+
+        return $data;
+    }
+
+    /**
+     * Get Hostname
+     *
+     * There are only two legal types of hostname - either a fully
+     * qualified domain name (eg: "mail.example.com") or an IP literal
+     * (eg: "[1.2.3.4]").
+     *
+     * @see https://tools.ietf.org/html/rfc5321#section-2.3.5
+     * @see http://cbl.abuseat.org/namingproblems.html
+     *
+     * @return string
+     */
+    protected function getHostname()
+    {
+        if (isset($_SERVER['SERVER_NAME'])) {
+            return $_SERVER['SERVER_NAME'];
+        }
+
+        return isset($_SERVER['SERVER_ADDR']) ? '[' . $_SERVER['SERVER_ADDR'] . ']' : '[127.0.0.1]';
+    }
+
+    /**
+     * Get Debug Message
+     *
+     * @param array $include List of raw data chunks to include in the output
+     *                       Valid options are: 'headers', 'subject', 'body'
+     *
+     * @return string
+     */
+    public function printDebugger($include = ['headers', 'subject', 'body'])
+    {
+        $msg = implode('', $this->debugMessage);
+
+        // Determine which parts of our raw data needs to be printed
+        $raw_data                      = '';
+        is_array($include) || $include = [$include];
+
+        in_array('headers', $include, true) && $raw_data = htmlspecialchars($this->headerStr) . "\n";
+        in_array('subject', $include, true) && $raw_data .= htmlspecialchars($this->subject) . "\n";
+        in_array('body', $include, true) && $raw_data    .= htmlspecialchars($this->finalBody);
+
+        return $msg . ($raw_data === '' ? '' : '<pre>' . $raw_data . '</pre>');
+    }
+
+    /**
+     * Set Message
+     *
+     * @param string $msg
+     */
+    protected function setErrorMessage($msg)
+    {
+        $this->debugMessage[] = $msg . '<br />';
+    }
+
+    /**
+     * Mime Types
+     *
+     * @param string $ext
+     *
+     * @return string
+     */
+    protected function mimeTypes($ext = '')
+    {
+        $mime = Mimes::guessTypeFromExtension(strtolower($ext));
+
+        return ! empty($mime) ? $mime : 'application/x-unknown-content-type';
+    }
+
+    /**
+     * Destructor
+     */
+    public function __destruct()
+    {
+        is_resource($this->SMTPConnect) && $this->sendCommand('quit');
+    }
+
+    /**
+     * Byte-safe strlen()
+     *
+     * @param string $str
+     *
+     * @return int
+     */
+    protected static function strlen($str)
+    {
+        return (static::$func_overload) ? mb_strlen($str, '8bit') : strlen($str);
+    }
+
+    /**
+     * Byte-safe substr()
+     *
+     * @param string   $str
+     * @param int      $start
+     * @param int|null $length
+     *
+     * @return string
+     */
+    protected static function substr($str, $start, $length = null)
+    {
+        if (static::$func_overload) {
+            return mb_substr($str, $start, $length, '8bit');
+        }
+
+        return isset($length) ? substr($str, $start, $length) : substr($str, $start);
+    }
 }
diff --git a/system/Mailer/Handlers/SendmailHandler.php b/system/Mailer/Handlers/SendmailHandler.php
index 35d24cf07d14..29bf39f72499 100644
--- a/system/Mailer/Handlers/SendmailHandler.php
+++ b/system/Mailer/Handlers/SendmailHandler.php
@@ -1,12 +1,12 @@
 <?php
 
 /**
- * This file is part of the CodeIgniter 4 framework.
+ * This file is part of CodeIgniter 4 framework.
  *
  * (c) CodeIgniter Foundation <admin@codeigniter.com>
  *
- * For the full copyright and license information, please view the LICENSE
- * file that was distributed with this source code.
+ * For the full copyright and license information, please view
+ * the LICENSE file that was distributed with this source code.
  */
 
 namespace CodeIgniter\Mailer\Handlers;
@@ -16,67 +16,58 @@
 
 class SendmailHandler extends BaseHandler
 {
-	/**
-	 * Whether this handler is supported on this system.
-	 *
-	 * @return boolean
-	 */
-	public function isSupported(): bool
-	{
-		return true;
-	}
+    /**
+     * Whether this handler is supported on this system.
+     */
+    public function isSupported(): bool
+    {
+        return true;
+    }
 
-	/**
-	 * Spools an Email to the server.
-	 *
-	 * @param Email $email
-	 *
-	 * @return boolean
-	 */
-	protected function spool(Email $email)
-	{
-	}
+    /**
+     * Spools an Email to the server.
+     *
+     * @return bool
+     */
+    protected function spool(Email $email)
+    {
+    }
 
-	//--------------------------------------------------------------------
+    //--------------------------------------------------------------------
 
-/* WIP */
+    // WIP
 
-	/**
-	 * Send using Sendmail
-	 *
-	 * @return boolean
-	 */
-	protected function sendWithSendmail()
-	{
-		// _validate_email_for_shell() below accepts by reference,
-		// so this needs to be assigned to a variable
-		$from = $this->cleanEmail($this->headers['From']);
-		if ($this->validateEmailForShell($from))
-		{
-			$from = '-f ' . $from;
-		}
-		else
-		{
-			$from = '';
-		}
+    /**
+     * Send using Sendmail
+     *
+     * @return bool
+     */
+    protected function sendWithSendmail()
+    {
+        // _validate_email_for_shell() below accepts by reference,
+        // so this needs to be assigned to a variable
+        $from = $this->cleanEmail($this->headers['From']);
+        if ($this->validateEmailForShell($from)) {
+            $from = '-f ' . $from;
+        } else {
+            $from = '';
+        }
 
-		// is popen() enabled?
-		if (! function_usable('popen') || false === ($fp = @popen($this->mailPath . ' -oi ' . $from . ' -t', 'w')))
-		{
-			// server probably has popen disabled, so nothing we can do to get a verbose error.
-			return false;
-		}
+        // is popen() enabled?
+        if (! function_usable('popen') || false === ($fp = @popen($this->mailPath . ' -oi ' . $from . ' -t', 'w'))) {
+            // server probably has popen disabled, so nothing we can do to get a verbose error.
+            return false;
+        }
 
-		fputs($fp, $this->headerStr);
-		fputs($fp, $this->finalBody);
+        fwrite($fp, $this->headerStr);
+        fwrite($fp, $this->finalBody);
 
-		$status = pclose($fp);
+        $status = pclose($fp);
 
-		if ($status !== 0)
-		{
-			throw MailerException::forNosocket($status);
-		}
+        if ($status !== 0) {
+            throw MailerException::forNosocket($status);
+        }
 
-		return true;
-	}
+        return true;
+    }
 }
diff --git a/system/Mailer/MailerInterface.php b/system/Mailer/MailerInterface.php
index 3f5390ceddf6..7916753a634d 100644
--- a/system/Mailer/MailerInterface.php
+++ b/system/Mailer/MailerInterface.php
@@ -1,12 +1,12 @@
 <?php
 
 /**
- * This file is part of the CodeIgniter 4 framework.
+ * This file is part of CodeIgniter 4 framework.
  *
  * (c) CodeIgniter Foundation <admin@codeigniter.com>
  *
- * For the full copyright and license information, please view the LICENSE
- * file that was distributed with this source code.
+ * For the full copyright and license information, please view
+ * the LICENSE file that was distributed with this source code.
  */
 
 namespace CodeIgniter\Mailer;
@@ -23,24 +23,18 @@
  */
 interface MailerInterface
 {
-	/**
-	 * Stores the Mailer config.
-	 *
-	 * @param Mailer $config
-	 */
-	public function __construct(Mailer $config);
+    /**
+     * Stores the Mailer config.
+     */
+    public function __construct(Mailer $config);
 
-	/**
-	 * Whether this handler is supported on this system.
-	 *
-	 * @return boolean
-	 */
-	public function isSupported(): bool;
+    /**
+     * Whether this handler is supported on this system.
+     */
+    public function isSupported(): bool;
 
-	/**
-	 * Sends an Email.
-	 *
-	 * @param Email $email
-	 */
-	public function send(Email $email);
+    /**
+     * Sends an Email.
+     */
+    public function send(Email $email);
 }

From 547fb221fc60464dfcd84b705168cbc389169c9c Mon Sep 17 00:00:00 2001
From: Lonnie Ezell <lonnieje@gmail.com>
Date: Mon, 25 Apr 2022 22:58:27 -0500
Subject: [PATCH 7/8] Additional Mailer/Address testing.

---
 system/Mailer/Address.php           | 44 ++++++++++----------
 tests/system/Mailer/AddressTest.php | 64 ++++++++++++++++++++++++++++-
 2 files changed, 84 insertions(+), 24 deletions(-)

diff --git a/system/Mailer/Address.php b/system/Mailer/Address.php
index b809dfb4d80d..8fb519528d3e 100644
--- a/system/Mailer/Address.php
+++ b/system/Mailer/Address.php
@@ -30,6 +30,22 @@ class Address
      */
     protected $name;
 
+    /**
+     * Validates the email and stores the values.
+     *
+     * @throws MailerException
+     */
+    final public function __construct(string $email, ?string $name = null)
+    {
+        $this->email = trim($email);
+
+        if (! service('validation')->check($this->email, 'required|valid_email')) {
+            throw MailerException::forInvalidAddress($email);
+        }
+
+        $this->name = isset($name) ? trim($name, self::TRIM) : null;
+    }
+
     /**
      * Creates a new Address from a simple or full email address string.
      *
@@ -90,36 +106,20 @@ final public static function split(string $address): array
      */
     final public static function merge(string $email, ?string $name = null): string
     {
+        $email = trim($email);
+
         if (null === $name) {
-            return trim($email);
+            return $email;
         }
 
-        // Enclose the email in angle brackets
-        $email = '<' . $email . '>';
-
         // If there is no name then finish
-        if ('' === $name = trim($name, self::TRIM)) {
+        $name = trim($name, self::TRIM);
+        if ($name === '') {
             return $email;
         }
 
         // Wrap the name in quotes and prepend it to the email
-        return '"' . $name . '" ' . $email;
-    }
-
-    /**
-     * Validates the email and stores the values.
-     *
-     * @throws MailerException
-     */
-    final public function __construct(string $email, ?string $name = null)
-    {
-        $this->email = trim($email);
-
-        if (! service('validation')->check($this->email, 'required|valid_email')) {
-            throw MailerException::forInvalidAddress($email);
-        }
-
-        $this->name = isset($name) ? trim($name, self::TRIM) : null;
+        return '"' . $name . '" <' . $email . '>';
     }
 
     public function getEmail(): string
diff --git a/tests/system/Mailer/AddressTest.php b/tests/system/Mailer/AddressTest.php
index 4e13acf53001..df0af86ae5ca 100644
--- a/tests/system/Mailer/AddressTest.php
+++ b/tests/system/Mailer/AddressTest.php
@@ -3,6 +3,8 @@
 namespace CodeIgniter\Mailer;
 
 use CodeIgniter\Test\CIUnitTestCase;
+use CodeIgniter\Mailer\Exceptions\MailerException;
+use Config\Mailer;
 
 class AddressTest extends CIUnitTestCase
 {
@@ -13,7 +15,7 @@ public function testConstructor(string $email, ?string $emailResult, ?string $na
 	{
 		if (is_null($emailResult))
 		{
-			$this->expectException('InvalidArgumentException');
+			$this->expectException(MailerException::class);
 			$this->expectExceptionMessage(lang('Mailer.invalidAddress', [$email]));
 		}
 
@@ -84,7 +86,7 @@ public function testCreate($address, ?string $emailResult, ?string $nameResult)
 	{
 		if (is_null($emailResult))
 		{
-			$this->expectException('InvalidArgumentException');
+			$this->expectException(MailerException::class);
 			$this->expectExceptionMessage(lang('Mailer.invalidAddress', ['']));
 		}
 
@@ -134,4 +136,62 @@ public function addressProvider(): array
 			],
 		];
 	}
+
+    /**
+     * @dataProvider userProvider
+     */
+    public function testMerge(string $email, ?string $name, string $expected)
+    {
+        $this->assertEquals($expected, Address::merge($email, $name));
+    }
+
+    /**
+     * @dataProvider userProvider
+     */
+    public function testStringify(string $email, ?string $name, string $expected)
+    {
+        $address = new Address($email, $name);
+        $this->assertEquals($expected, (string)$address);
+    }
+
+    public function userProvider()
+    {
+        return [
+            'emailOnly' => [
+                'leia@alderaan.org',
+                null,
+                'leia@alderaan.org'
+            ],
+            'emailOnlySpace' => [
+                ' leia@alderaan.org ',
+                null,
+                'leia@alderaan.org'
+            ],
+            'spaceName' => [
+                ' leia@alderaan.org ',
+                ' ',
+                'leia@alderaan.org'
+            ],
+            'simpleName' => [
+                'leia@alderaan.org',
+                'Leia',
+                '"Leia" <leia@alderaan.org>'
+            ],
+            'simpleNameSpaced' => [
+                'leia@alderaan.org',
+                ' Leia ',
+                '"Leia" <leia@alderaan.org>'
+            ],
+            'simpleEmailSpaced' => [
+                ' leia@alderaan.org ',
+                ' Leia ',
+                '"Leia" <leia@alderaan.org>'
+            ],
+            'quotedName' => [
+                'leia@alderaan.org',
+                'Princess Leia',
+                '"Princess Leia" <leia@alderaan.org>'
+            ],
+        ];
+    }
 }

From 7ec7c1779efdb5159f83b076491f32b99b3d37cd Mon Sep 17 00:00:00 2001
From: Lonnie Ezell <lonnieje@gmail.com>
Date: Tue, 31 May 2022 23:00:21 -0500
Subject: [PATCH 8/8] wip

---
 system/Mailer/Address.php              |   2 +-
 system/Mailer/Email.php                |  85 +++++--
 system/Mailer/Encode.php               |  65 +++--
 system/Mailer/Handlers/BaseHandler.php |   4 +-
 tests/system/Mailer/AddressTest.php    |  33 +++
 tests/system/Mailer/AttachmentTest.php |  33 +++
 tests/system/Mailer/EmailTest.php      | 327 ++++++++++++++++++++++++-
 tests/system/Mailer/EncodeTest.php     |  84 +++++++
 tests/system/Mailer/MailerTest.php     |   2 +-
 9 files changed, 592 insertions(+), 43 deletions(-)
 create mode 100644 tests/system/Mailer/AttachmentTest.php
 create mode 100644 tests/system/Mailer/EncodeTest.php

diff --git a/system/Mailer/Address.php b/system/Mailer/Address.php
index 8fb519528d3e..787654cb1506 100644
--- a/system/Mailer/Address.php
+++ b/system/Mailer/Address.php
@@ -73,7 +73,7 @@ public static function createArray(array $addresses)
             $element = reset($addresses);
 
             if (is_string($element) && strpos($element, ',') !== false) {
-                $addresses = preg_split('/[\s,]/', $element, -1, PREG_SPLIT_NO_EMPTY);
+                $addresses = preg_split('/[\n\t\v,]/', $element, -1, PREG_SPLIT_NO_EMPTY);
             }
         }
 
diff --git a/system/Mailer/Email.php b/system/Mailer/Email.php
index d0d20b675c7f..accb01f869e1 100644
--- a/system/Mailer/Email.php
+++ b/system/Mailer/Email.php
@@ -21,6 +21,9 @@
  *
  * Represents a single email message.
  * This class extends HTTP\Message and uses headers for most storage and retrieval.
+ *
+ * @see https://datatracker.ietf.org/doc/html/rfc5322
+ * @see https://datatracker.ietf.org/doc/html/rfc2047
  */
 class Email extends Message
 {
@@ -45,7 +48,7 @@ class Email extends Message
      *
      * @var Attachment[]
      */
-    protected $attachements = [];
+    protected $attachments = [];
 
     /**
      * This email's unique Message ID.
@@ -104,8 +107,8 @@ public function set(array $data, bool $overwrite = true): self
             $getter = 'get' . ucfirst($setter);
 
             if (array_key_exists($setter, $data)) {
-                if ($overwrite || null === $this->{$getter}()) {
-                    $this->{$method}($data[$method]);
+                if ($overwrite || $this->{$getter}() === null) {
+                    $this->{$setter}($data[$setter]);
                 }
             }
         }
@@ -130,7 +133,7 @@ public function getHeaderString(string $newline = "\r\n", ?array $exclude = null
             if (isset($exclude) && in_array($name, $exclude, true)) {
                 continue;
             }
-            // Check includion
+            // Check inclusion
             if (isset($include) && ! in_array($name, $include, true)) {
                 continue;
             }
@@ -140,12 +143,14 @@ public function getHeaderString(string $newline = "\r\n", ?array $exclude = null
                 $string .= implode(',', array_map('__toString', $value));
             } elseif (is_array($value)) {
                 foreach ($value as $header) {
-                    $string .= $header . $this->newline;
+                    $string .= $header . $newline;
                 }
             } else {
-                $string .= $value . $this->newline; // Trailing newline is intentional
+                $string .= (string)$value->getValue() . $newline; // Trailing newline is intentional
             }
         }
+
+        return $string;
     }
 
     //--------------------------------------------------------------------
@@ -183,9 +188,13 @@ public function subject(string $subject)
     /**
      * @return $this
      */
-    public function from(string $address)
+    public function from(string $address, ?string $name=null)
     {
-        return $this->setHeader('From', Address::create($address));
+        $addr = $name !== null
+            ? new Address($address, $name)
+            : Address::create($address);
+
+        return $this->setHeader('From', $addr);
     }
 
     /**
@@ -195,6 +204,12 @@ public function from(string $address)
      */
     public function to(...$addresses)
     {
+        // If an array of address was pushed in
+        // break it out so we get only the actual emails
+        if($addresses[0] && is_array($addresses[0])) {
+            $addresses = $addresses[0];
+        }
+
         return $this->setHeader('To', Address::createArray($addresses));
     }
 
@@ -205,6 +220,12 @@ public function to(...$addresses)
      */
     public function cc(...$addresses)
     {
+        // If an array of address was pushed in
+        // break it out so we get only the actual emails
+        if($addresses[0] && is_array($addresses[0])) {
+            $addresses = $addresses[0];
+        }
+
         return $this->setHeader('Cc', Address::createArray($addresses));
     }
 
@@ -215,15 +236,25 @@ public function cc(...$addresses)
      */
     public function bcc(...$addresses)
     {
+        // If an array of address was pushed in
+        // break it out so we get only the actual emails
+        if($addresses[0] && is_array($addresses[0])) {
+            $addresses = $addresses[0];
+        }
+
         return $this->setHeader('Bcc', Address::createArray($addresses));
     }
 
     /**
      * @return $this
      */
-    public function replyTo(string $address)
+    public function replyTo(string $address, ?string $name=null)
     {
-        return $this->setHeader('From', Address::create($address));
+        $addr = $name !== null
+            ? new Address($address, $name)
+            : Address::create($address);
+
+        return $this->setHeader('Reply-To', $addr);
     }
 
     /**
@@ -266,12 +297,12 @@ public function date(DateTimeInterface $date)
 
     public function getSubject(): ?string
     {
-        return $this->hasHeader('Subject') ? $this->getHeader('Subject')->getValue() : null;
+        return $this->hasHeader('Subject') ? $this->header('Subject')->getValue() : null;
     }
 
     public function getFrom(): ?Address
     {
-        return $this->hasHeader('From') ? Address::create($this->getHeader('From')->getValue()) : null;
+        return $this->hasHeader('From') ? Address::create($this->header('From')->getValue()) : null;
     }
 
     /**
@@ -279,7 +310,7 @@ public function getFrom(): ?Address
      */
     public function getTo(): ?array
     {
-        return $this->hasHeader('To') ? Address::createArray($this->getHeader('To')->getValue()) : null;
+        return $this->hasHeader('To') ? Address::createArray($this->header('To')->getValue()) : null;
     }
 
     /**
@@ -287,7 +318,7 @@ public function getTo(): ?array
      */
     public function getCc(): ?array
     {
-        return $this->hasHeader('Cc') ? Address::createArray($this->getHeader('Cc')->getValue()) : null;
+        return $this->hasHeader('Cc') ? Address::createArray($this->header('Cc')->getValue()) : null;
     }
 
     /**
@@ -295,12 +326,12 @@ public function getCc(): ?array
      */
     public function getBcc(): ?array
     {
-        return $this->hasHeader('Bcc') ? Address::createArray($this->getHeader('Bcc')->getValue()) : null;
+        return $this->hasHeader('Bcc') ? Address::createArray($this->header('Bcc')->getValue()) : null;
     }
 
     public function getReplyTo(): ?Address
     {
-        return $this->hasHeader('Reply-To') ? Address::create($this->getHeader('Reply-To')->getValue()) : null;
+        return $this->hasHeader('Reply-To') ? Address::create($this->header('Reply-To')->getValue()) : null;
     }
 
     public function getReturnPath(): ?Address
@@ -310,7 +341,7 @@ public function getReturnPath(): ?Address
         }
 
         // Get just the email portion of the stored address
-        $address = $this->getHeader('Return-Path')->getValue();
+        $address = $this->header('Return-Path')->getValue();
         $email   = Address::split($address)['email'];
 
         // Force Address to use angle braces by giving an empty display name
@@ -326,7 +357,7 @@ public function getReturnPath(): ?Address
     public function getPriority(): ?int
     {
         if ($this->hasHeader('X-Priority')) {
-            return array_search($this->getHeader('X-Priority')->getValue(), self::PRIORITIES, true) ?: null;
+            return array_search($this->header('X-Priority')->getValue(), self::PRIORITIES, true) ?: null;
         }
 
         return null;
@@ -334,7 +365,7 @@ public function getPriority(): ?int
 
     public function getDate(): ?Time
     {
-        return $this->hasHeader('Date') ? Time::parse($this->getHeader('Date')->getValue()) : null;
+        return $this->hasHeader('Date') ? Time::parse($this->header('Date')->getValue()) : null;
     }
 
     /**
@@ -343,7 +374,7 @@ public function getDate(): ?Time
      */
     public function getMessageId(): ?string
     {
-        if (null === $this->messageId && $returnPath = $this->getReturnPath()) {
+        if ($this->messageId === null && $returnPath = $this->getReturnPath()) {
             // Use a unique ID with the same domain as the Return-Path email
             $this->messageId = '<' . uniqid('', true) . strstr($returnPath->getEmail(), '@') . '>';
         }
@@ -434,6 +465,20 @@ public function setMessage($body): self
         return $this->body($body);
     }
 
+    /**
+     * Sets a header and it's value.
+     *
+     * Extends the default 
+     *
+     * @param array|string|null $value
+     *
+     * @return $this
+     */
+    public function setHeader(string $name, $value): self
+    {
+
+    }
+
     /**
      * Magic method to allow CI3-style methods (like "setReplyTo()") to
      * forward to their equivalent setters.
diff --git a/system/Mailer/Encode.php b/system/Mailer/Encode.php
index 51be89ea2d3f..b7870ee3d019 100644
--- a/system/Mailer/Encode.php
+++ b/system/Mailer/Encode.php
@@ -159,33 +159,64 @@ public function address(Address $address): Address
 
     /**
      * Performs "Q Encoding" on a string for use in email headers.
-     * This is mostly straight from CodeIgniter 3.
+     * It's related but not identical to quoted-printable, so it has its
+     * own method.
      *
-     * @see https://www.freesoft.org/CIE/RFC/1522/6.htm
+     * @param string $str
+     *
+     * @return string
      */
-    public function Q(string $string): string
+    protected function Q($str)
     {
-        $string = str_replace(["\r", "\n"], '', $string);
-        $output = '=?' . $this->charset . '?Q?';
-        $chars  = $this->charset === 'UTF-8' ? mb_strlen($string, 'UTF-8') : mb_strlen($string, '8bit');
-        $length = mb_strlen($output, '8bit');
+        $str = str_replace(["\r", "\n"], '', $str);
+
+        if ($this->charset === 'UTF-8') {
+            // Note: We used to have mb_encode_mimeheader() as the first choice
+            // here, but it turned out to be buggy and unreliable. DO NOT
+            // re-add it! -- Narf
+            if (extension_loaded('iconv')) {
+                $output = @iconv_mime_encode('', $str, [
+                    'scheme'           => 'Q',
+                    'line-length'      => 76,
+                    'input-charset'    => $this->charset,
+                    'output-charset'   => $this->charset,
+                    'line-break-chars' => $this->CRLF,
+                ]);
+
+                // There are reports that iconv_mime_encode() might fail and return FALSE
+                if ($output !== false) {
+                    // iconv_mime_encode() will always put a header field name.
+                    // We've passed it an empty one, but it still prepends our
+                    // encoded string with ': ', so we need to strip it.
+                    return static::substr($output, 2);
+                }
 
-        for ($i = 0; $i < $chars; $i++) {
-            $chr = ($this->charset === 'UTF-8' && extension_loaded('iconv'))
-                ? '=' . implode('=', str_split(strtoupper(bin2hex(iconv_substr($string, $i, 1, $this->charset))), 2))
-                : '=' . strtoupper(bin2hex($string[$i]));
+                $chars = iconv_strlen($str, 'UTF-8');
+            } elseif (extension_loaded('mbstring')) {
+                $chars = mb_strlen($str, 'UTF-8');
+            }
+        }
+
+        // We might already have this set for UTF-8
+        if (! isset($chars)) {
+            $chars = static::strlen($str);
+        }
+
+        $output = '=?' . $this->charset . '?Q?';
 
-            $chrlen = mb_strlen($chr, '8bit');
+        for ($i = 0, $length = static::strlen($output); $i < $chars; $i++) {
+            $chr = ($this->charset === 'UTF-8' && extension_loaded('iconv')) ? '=' . implode('=', str_split(strtoupper(bin2hex(iconv_substr($str, $i, 1, $this->charset))), 2)) : '=' . strtoupper(bin2hex($str[$i]));
 
-            // RFC 2045 sets a limit of 76 characters per line, but leave space for ?= at the end of each line
-            if ($length + $chrlen > 74) {
-                $output .= '?=' . $this->crlf // EOL
+            // RFC 2045 sets a limit of 76 characters per line.
+            // We'll append ?= to the end of each line though.
+            if ($length + ($l = static::strlen($chr)) > 74) {
+                $output .= '?=' . $this->CRLF // EOL
                     . ' =?' . $this->charset . '?Q?' . $chr; // New line
 
-                $length = 6 + mb_strlen($this->charset, '8bit') + $chrlen; // Reset the length for the new line
+                $length = 6 + static::strlen($this->charset) + $l; // Reset the length for the new line
             } else {
                 $output .= $chr;
-                $length += $chrlen;
+                $length += $l;
             }
         }
 
diff --git a/system/Mailer/Handlers/BaseHandler.php b/system/Mailer/Handlers/BaseHandler.php
index 9fa2aafe0420..097a55591caf 100644
--- a/system/Mailer/Handlers/BaseHandler.php
+++ b/system/Mailer/Handlers/BaseHandler.php
@@ -16,6 +16,8 @@
 use CodeIgniter\Mailer\Exceptions\MailerException;
 use CodeIgniter\Mailer\MailerInterface;
 use Config\Mailer;
+use CodeIgniter\Mailer\Encode;
+use CodeIgniter\Mailer\Format;
 
 /**
  * Mail Handler
@@ -30,7 +32,7 @@ abstract class BaseHandler implements MailerInterface
      *
      * @var string
      */
-    protected $protocol;
+    protected string $protocol;
 
     /**
      * The Mailer config.
diff --git a/tests/system/Mailer/AddressTest.php b/tests/system/Mailer/AddressTest.php
index df0af86ae5ca..441d6840bda8 100644
--- a/tests/system/Mailer/AddressTest.php
+++ b/tests/system/Mailer/AddressTest.php
@@ -137,6 +137,39 @@ public function addressProvider(): array
 		];
 	}
 
+    public function testCreateArray()
+    {
+        $addresses = [
+            'leia@alderaan.org',
+            '"Luke Skywalker" <luke@tatooine.org>',
+        ];
+
+        $created = Address::createArray($addresses);
+
+        $emails = array_map(function($addy) {
+            return $addy->getEmail();
+        }, $created);
+
+        $this->assertTrue(in_array('leia@alderaan.org', $emails));
+        $this->assertTrue(in_array('luke@tatooine.org', $emails));
+    }
+
+    public function testCreateArrayFromCSV()
+    {
+        $addresses = [
+            'leia@alderaan.org,"Luke Skywalker" <luke@tatooine.org>',
+        ];
+
+        $created = Address::createArray($addresses);
+
+        $emails = array_map(function($addy) {
+            return $addy->getEmail();
+        }, $created);
+
+        $this->assertTrue(in_array('leia@alderaan.org', $emails));
+        $this->assertTrue(in_array('luke@tatooine.org', $emails));
+    }
+
     /**
      * @dataProvider userProvider
      */
diff --git a/tests/system/Mailer/AttachmentTest.php b/tests/system/Mailer/AttachmentTest.php
new file mode 100644
index 000000000000..2b1cd6dff958
--- /dev/null
+++ b/tests/system/Mailer/AttachmentTest.php
@@ -0,0 +1,33 @@
+<?php
+
+namespace CodeIgniter\Mailer;
+
+use CodeIgniter\Test\CIUnitTestCase;
+
+class AttachmentTest extends CIUnitTestCase
+{
+    public function testConstructorSimple()
+    {
+        $attachment = new Attachment(__FILE__);
+
+        $this->assertSame('AttachmentTest.php', $attachment->getBasename());
+    }
+
+    public function testGetContentID()
+    {
+        $attachment = new Attachment(__FILE__);
+
+        $this->assertStringContainsString('AttachmentTest.php@', $attachment->getContentId());
+    }
+
+    public function testGetContent()
+    {
+        $attachment = new Attachment(__FILE__);
+
+        $body = $attachment->getContent();
+
+        $this->assertNotEmpty($body);
+        // Detect if string if base64_encoded
+        $this->assertTrue(preg_match('%^[a-zA-Z0-9/+]*={0,2}$%', $body) === 1);
+    }
+}
diff --git a/tests/system/Mailer/EmailTest.php b/tests/system/Mailer/EmailTest.php
index b718117aa9f0..5e6bae4c6c42 100644
--- a/tests/system/Mailer/EmailTest.php
+++ b/tests/system/Mailer/EmailTest.php
@@ -2,17 +2,338 @@
 
 namespace CodeIgniter\Mailer;
 
+use CodeIgniter\I18n\Time;
 use CodeIgniter\Test\CIUnitTestCase;
 
 class EmailTest extends CIUnitTestCase
 {
+    public function tearDown(): void
+	{
+		// Restore file permissions after unreadable attachment test
+		$thefile = SUPPORTPATH . 'Mailer/ci-logo-not-readable.png';
+		chmod($thefile, 0664);
+	}
+
+    //--------------------------------------------------------------------
+	// Test constructor & configs
+
+    public function testEmptyConstructor()
+    {
+        $email = new Email();
+
+        // Just to make sure it didn't crash
+        $this->assertInstanceOf(Email::class, $email);
+
+        $this->assertNull($email->getBody());
+        $this->assertNull($email->getSubject());
+        $this->assertNull($email->getFrom());
+        $this->assertNull($email->getTo());
+        $this->assertNull($email->getCc());
+        $this->assertNull($email->getBcc());
+        $this->assertNull($email->getReplyTo());
+        $this->assertNull($email->getReturnPath());
+        $this->assertNull($email->getPriority());
+        $this->assertNull($email->getDate());
+    }
+
 	public function testConstructorUsesData()
 	{
-		$address = 'leia@alderaan.org';
 		$email   = new Email([
-			'from' => $address,
+            'body' => 'Email body',
+            'subject' => 'The Rebels need you!',
+            'from' => 'leia@alderaan.org',
+            'to' => 'lukeskywalker@tattoine.org',
+            'cc' => '"Obi Wan Kenobi" <obiwan@tattoine.org>',
+            'bcc' => ['one@example.com', 'two@example.com'],
+            'replyTo' => 'no-reply@alderaan.org',
+            'returnPath' => 'bounces@alderaan.org',
+            'priority' => 2,
+            'date' => Time::now(),
+            'truth' => 'out there',
 		]);
 
-		$this->assertSame($address, (string) $email->getFrom());
+		$this->assertSame('Email body', (string) $email->getBody());
+		$this->assertSame('The Rebels need you!', (string) $email->getSubject());
+		$this->assertSame('leia@alderaan.org', (string) $email->getFrom());
+		$this->assertSame('lukeskywalker@tattoine.org', (string)$email->getTo()[0]);
+		$this->assertSame('"Obi Wan Kenobi" <obiwan@tattoine.org>', (string)$email->getCc()[0]);
+		$this->assertSame('one@example.com', (string)$email->getBcc()[0]);
+		$this->assertSame('no-reply@alderaan.org', (string)$email->getReplyTo());
+		$this->assertSame('bounces@alderaan.org', (string)$email->getReturnPath());
+		$this->assertSame(2, $email->getPriority());
+		$this->assertInstanceOf(Time::class, $email->getDate());
+	}
+
+    public function testSetters()
+    {
+        $email = new Email();
+
+        $email->body('Email body');
+        $email->subject('The Rebels need you!');
+        $email->from('leia@alderaan.org');
+        $email->to('lukeskywalker@tattoine.org');
+        $email->cc('"Obi Wan Kenobi" <obiwan@tattoine.org>');
+        $email->bcc('one@example.com', 'two@example.com');
+        $email->replyTo('no-reply@alderaan.org');
+        $email->returnPath('bounces@alderaan.org');
+        $email->priority(2);
+        $email->date(Time::now());
+
+        $this->assertSame('Email body', (string) $email->getBody());
+		$this->assertSame('The Rebels need you!', (string) $email->getSubject());
+		$this->assertSame('leia@alderaan.org', (string) $email->getFrom());
+		$this->assertSame('lukeskywalker@tattoine.org', (string)$email->getTo()[0]);
+		$this->assertSame('"Obi Wan Kenobi" <obiwan@tattoine.org>', (string)$email->getCc()[0]);
+		$this->assertSame('one@example.com', (string)$email->getBcc()[0]);
+		$this->assertSame('no-reply@alderaan.org', (string)$email->getReplyTo());
+		$this->assertSame('bounces@alderaan.org', (string)$email->getReturnPath());
+		$this->assertSame(2, $email->getPriority());
+		$this->assertInstanceOf(Time::class, $email->getDate());
+    }
+
+    public function testMessageId()
+    {
+        $email = new Email([
+            'returnPath' => 'no-reply@alderaan.org'
+        ]);
+
+        $this->assertMatchesRegularExpression("/^<(.*)@alderaan.org>/", $email->getMessageId());
+    }
+
+    public function testMessageIdReturnsNull()
+    {
+        $email = new Email();
+
+        $this->assertNull($email->getMessageId());
+    }
+
+    public function testGetBoundaryCreatesBoundary()
+    {
+        $email = new Email();
+
+        $this->assertStringContainsString('foo_', $email->getBoundary('foo'));
+    }
+
+    public function testCI3SetterMagic()
+    {
+        $email = new Email();
+
+        $email->setBody('Email body');
+        $email->setSubject('The Rebels need you!');
+        $email->setFrom('leia@alderaan.org');
+        $email->setTo('lukeskywalker@tattoine.org');
+        $email->setCc('"Obi Wan Kenobi" <obiwan@tattoine.org>');
+        $email->setBcc('one@example.com', 'two@example.com');
+        $email->setReplyTo('no-reply@alderaan.org');
+        $email->setReturnPath('bounces@alderaan.org');
+        $email->setPriority(2);
+        $email->setDate(Time::now());
+
+        $this->assertSame('Email body', (string) $email->getBody());
+		$this->assertSame('The Rebels need you!', (string) $email->getSubject());
+		$this->assertSame('leia@alderaan.org', (string) $email->getFrom());
+		$this->assertSame('lukeskywalker@tattoine.org', (string)$email->getTo()[0]);
+		$this->assertSame('"Obi Wan Kenobi" <obiwan@tattoine.org>', (string)$email->getCc()[0]);
+		$this->assertSame('one@example.com', (string)$email->getBcc()[0]);
+		$this->assertSame('no-reply@alderaan.org', (string)$email->getReplyTo());
+		$this->assertSame('bounces@alderaan.org', (string)$email->getReturnPath());
+		$this->assertSame(2, $email->getPriority());
+		$this->assertInstanceOf(Time::class, $email->getDate());
+    }
+
+    public function testSetMessage()
+    {
+        $email = new Email();
+
+        $email->setMessage('Email body');
+
+        $this->assertSame('Email body', $email->getBody());
+    }
+
+    //--------------------------------------------------------------------
+	// Test setting the "from" property
+    // NOTE: Return-Path should NOT be automatically set,
+    //      see: https://www.postmastery.com/about-the-return-path-header/
+
+	public function testSetFromMailerOnly()
+	{
+		$email = new Email();
+		$email->from('leia@alderaan.org');
+		$this->assertEquals('leia@alderaan.org', (string)$email->getFrom());
+		$this->assertNull($email->header('Return-Path'));
+	}
+
+	public function testSetFromMailerAndName()
+	{
+		$email = new Email();
+		$email->from('leia@alderaan.org', 'Princess Leia');
+		$this->assertEquals('"Princess Leia" <leia@alderaan.org>', $email->getFrom());
+	}
+
+    public function testSetFromMailerAndNameString()
+	{
+		$email = new Email();
+		$email->from('"Princess Leia" <leia@alderaan.org>');
+		$this->assertEquals('"Princess Leia" <leia@alderaan.org>', (string)$email->getFrom());
+	}
+
+    //--------------------------------------------------------------------
+	// Test setting the "replyTo" property
+
+	public function testSetReplyToMailerOnly()
+	{
+		$mailer = new Email();
+		$mailer->setReplyTo('leia@alderaan.org');
+		$this->assertEquals('leia@alderaan.org', (string)$mailer->getReplyTo());
+	}
+
+	public function testSetReplyToMailerAndName()
+	{
+		$mailer = new Email();
+		$mailer->setReplyTo('leia@alderaan.org', 'Princess Leia');
+		$this->assertEquals('"Princess Leia" <leia@alderaan.org>', (string)$mailer->getReplyTo());
+	}
+
+    //--------------------------------------------------------------------
+	// Test setting the "to" property
+
+	public function testSetToBasic()
+	{
+		$mailer = new Email();
+		$mailer->setTo('Luke <luke@tatooine.org>');
+
+        $emails = array_map(function($addy) {
+            return $addy->getEmail();
+        }, $mailer->getTo());
+
+		$this->assertTrue(in_array('luke@tatooine.org', $emails));
+	}
+
+    public function testSetToMultiple()
+	{
+		$mailer = new Email();
+		$mailer->setTo('Luke <luke@tatooine.org>', 'padme@naboo.org');
+
+        $emails = array_map(function($addy) {
+            return $addy->getEmail();
+        }, $mailer->getTo());
+
+		$this->assertTrue(in_array('luke@tatooine.org', $emails));
+		$this->assertTrue(in_array('padme@naboo.org', $emails));
+	}
+
+	public function testSetToArray()
+	{
+		$mailer = new Email();
+		$mailer->setTo(['Luke <luke@tatooine.org>', 'padme@naboo.org']);
+
+        $emails = array_map(function($addy) {
+            return $addy->getEmail();
+        }, $mailer->getTo());
+
+		$this->assertTrue(in_array('luke@tatooine.org', $emails));
+		$this->assertTrue(in_array('padme@naboo.org', $emails));
+	}
+
+    //--------------------------------------------------------------------
+	// Test setting the "cc" property (copied recipients)
+
+	public function testSetCCBasic()
+	{
+		$mailer = new Email();
+        $mailer->cc('Luke <luke@tatooine.org>');
+
+        $emails = array_map(function($addy) {
+            return $addy->getEmail();
+        }, $mailer->getCc());
+
+		$this->assertTrue(in_array('luke@tatooine.org', $emails));
+	}
+
+    public function testSetCCMultiple()
+	{
+		$mailer = new Email();
+		$mailer->cc('Luke <luke@tatooine.org>', 'padme@naboo.org');
+
+        $emails = array_map(function($addy) {
+            return $addy->getEmail();
+        }, $mailer->getCc());
+
+		$this->assertTrue(in_array('luke@tatooine.org', $emails));
+		$this->assertTrue(in_array('padme@naboo.org', $emails));
+	}
+
+	public function testSetCCArray()
+	{
+		$mailer = new Email();
+		$mailer->cc(['Luke <luke@tatooine.org>', 'padme@naboo.org']);
+
+        $emails = array_map(function($addy) {
+            return $addy->getEmail();
+        }, $mailer->getCc());
+
+		$this->assertTrue(in_array('luke@tatooine.org', $emails));
+		$this->assertTrue(in_array('padme@naboo.org', $emails));
+	}
+
+    //--------------------------------------------------------------------
+	// Test setting the "bcc" property (blind-copied recipients)
+
+	public function testSetBCCBasic()
+	{
+		$mailer = new Email();
+		$mailer->bcc('Luke <luke@tatooine.org>');
+
+        $emails = array_map(function($addy) {
+            return $addy->getEmail();
+        }, $mailer->getBcc());
+
+		$this->assertTrue(in_array('luke@tatooine.org', $emails));
+	}
+
+    public function testSetBCCMultiple()
+	{
+		$mailer = new Email();
+		$mailer->bcc('Luke <luke@tatooine.org>', 'padme@naboo.org');
+
+        $emails = array_map(function($addy) {
+            return $addy->getEmail();
+        }, $mailer->getBcc());
+
+		$this->assertTrue(in_array('luke@tatooine.org', $emails));
+		$this->assertTrue(in_array('padme@naboo.org', $emails));
+	}
+
+	public function testSetBCCArray()
+	{
+		$mailer = new Email();
+		$mailer->bcc(['Luke <luke@tatooine.org>', 'padme@naboo.org']);
+
+        $emails = array_map(function($addy) {
+            return $addy->getEmail();
+        }, $mailer->getBcc());
+
+		$this->assertTrue(in_array('luke@tatooine.org', $emails));
+		$this->assertTrue(in_array('padme@naboo.org', $emails));
+	}
+
+    //--------------------------------------------------------------------
+	// Test setting the subject
+
+	public function testSetSubject()
+	{
+		$mailer    = new Email();
+		$original = 'Just a silly love song';
+		$mailer->setSubject($original);
+		$this->assertEquals($original, $mailer->header('Subject')->getValue());
+	}
+
+	public function testSetEncodedSubject()
+	{
+		$mailer    = new Email();
+		$original = 'Just a silly Leià song';
+		$expected = '=?UTF-8?Q?Just=20a=20silly=20Lei=C3=A0=20s?==?UTF-8?Q?ong?=';
+		$mailer->setSubject($original);
+		$this->assertEquals($expected, $mailer->header('Subject')->getValue());
 	}
 }
diff --git a/tests/system/Mailer/EncodeTest.php b/tests/system/Mailer/EncodeTest.php
new file mode 100644
index 000000000000..7d662906b7f5
--- /dev/null
+++ b/tests/system/Mailer/EncodeTest.php
@@ -0,0 +1,84 @@
+<?php
+
+namespace CodeIgniter\Mailer;
+
+use CodeIgniter\Test\CIUnitTestCase;
+
+class EncodeTest extends CIUnitTestCase
+{
+    public function qEncodingProvider()
+    {
+        return [
+            'Encode for text; char encoding default (iso88591)' => [
+                'input'    => "\xa1Hola! Se\xf1or!",
+                'expected' => '=A1Hola!_Se=F1or!',
+                'position' => 'text',
+            ],
+            'Encode for TEXT (uppercase); char encoding default (iso88591)' => [
+                'input'    => "\xa1Hola! Se\xf1or!",
+                'expected' => '=A1Hola!_Se=F1or!',
+                'position' => 'TEXT',
+            ],
+            'Encode for comment; char encoding default (iso88591)' => [
+                'input'    => "\xa1Hola! Se\xf1or!",
+                'expected' => '=A1Hola!_Se=F1or!',
+                'position' => 'comment',
+            ],
+            'Encode for Phrase (mixed case); char encoding default (iso88591)' => [
+                'input'    => "\xa1Hola! Se\xf1or!",
+                'expected' => '=A1Hola!_Se=F1or!',
+                'position' => 'Phrase',
+            ],
+            'Encode for text; char encoding explicit: utf-8' => [
+                'input'    => "\xc2\xa1Hola! Se\xc3\xb1or!",
+                'expected' => '=C2=A1Hola!_Se=C3=B1or!',
+                'position' => 'text',
+                'charset'  => 'utf-8',
+            ],
+            'Encode for text; char encoding explicit: utf-8; string contains "=" character' => [
+                'input'    => "Nov\xc3\xa1=",
+                'expected' => 'Nov=C3=A1=3D',
+                'position' => 'text',
+                'charset'  => 'utf-8',
+            ],
+            'Encode for text; char encoding default (iso88591); string containing new lines' => [
+                'input'    => "\xa1Hola!\r\nSe\xf1or!\r\n",
+                'expected' => '=A1Hola!Se=F1or!',
+                'position' => 'text',
+            ],
+            'Encode for text; char encoding explicit: utf-8; phrase vs text regex (text)' => [
+                'input'    => "Hello?\xbdWorld\x5e\xa9",
+                'expected' => 'Hello=3F=BDWorld^=A9',
+                'position' => 'text',
+                'charset'  => 'UTF-8',
+            ],
+        ];
+    }
+
+    /**
+     * @dataProvider qEncodingProvider
+     *
+     * @param string $input    The text to encode.
+     * @param string $expected The expected function return value.
+     * @param string $charset  Optional. The charset to use.
+     */
+    public function testQEncode(string $input, string $expected, ?string $position = null, ?string $charset = null)
+    {
+        $config = config('Mailer');
+        $config->charset = ! empty($charset) ? $charset : $config->charset;
+        $encoder = new Encode($config);
+
+        $result = $encoder->Q($input);
+
+        self::assertSame($expected, $result);
+    }
+
+    public function testQuotedPrintable()
+    {
+        $encoder = new Encode(config('Mailer'));
+        $string = 'Möchten Sie ein paar Äpfel?';
+        $expected = "M=C3=B6chten Sie ein paar =C3=84pfel?";
+
+        $this->assertEquals($expected, $encoder->quotedPrintable($string));
+    }
+}
diff --git a/tests/system/Mailer/MailerTest.php b/tests/system/Mailer/MailerTest.php
index 02eb92321407..b68088b5facd 100644
--- a/tests/system/Mailer/MailerTest.php
+++ b/tests/system/Mailer/MailerTest.php
@@ -4,7 +4,7 @@
 
 class MailerTest extends CIUnitTestCase
 {
-	public function tearDown()
+	public function tearDown(): void
 	{
 		// Restore file permissions after unreadable attachment test
 		$thefile = SUPPORTPATH . 'Mailer/ci-logo-not-readable.png';