main.cf

# See /usr/share/postfix/main.cf.dist for a commented, more complete version


# Debian specific:  Specifying a file name will cause the first
# line of that file to be used as the name.  The Debian default
# is /etc/mailname.
#myorigin = /etc/mailname

smtpd_banner = $myhostname Service ready
biff = no

# appending .domain is the MUA's job.
append_dot_mydomain = no

# Uncomment the next line to generate "delayed mail" warnings
#delay_warning_time = 4h

readme_directory = no

# -- TLS for incoming connections
###############################################################################
smtpd_use_tls = yes

smtpd_tls_security_level = may
smtpd_tls_auth_only = yes
smtpd_tls_chain_files =
    /etc/yunohost/certs/{{ main_domain }}/key.pem,
    /etc/yunohost/certs/{{ main_domain }}/crt.pem

tls_server_sni_maps = hash:/etc/postfix/sni

{% if compatibility == "intermediate" %}
# generated 2023-06-13, Mozilla Guideline v5.7, Postfix 3.7.5, OpenSSL 3.0.9, intermediate configuration
# https://ssl-config.mozilla.org/#server=postfix&version=3.7.5&config=intermediate&openssl=3.0.9&guideline=5.7

smtpd_tls_mandatory_protocols = !SSLv2, !SSLv3, !TLSv1, !TLSv1.1
smtpd_tls_protocols = !SSLv2, !SSLv3, !TLSv1, !TLSv1.1
smtpd_tls_mandatory_ciphers = medium

# curl https://ssl-config.mozilla.org/ffdhe2048.txt > /path/to/dhparam.pem
# not actually 1024 bits, this applies to all DHE >= 1024 bits
smtpd_tls_dh1024_param_file = /usr/share/yunohost/ffdhe2048.pem

tls_medium_cipherlist = ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-CHACHA20-POLY1305:ECDHE-RSA-CHACHA20-POLY1305:DHE-RSA-AES128-GCM-SHA256:DHE-RSA-AES256-GCM-SHA384:DHE-RSA-CHACHA20-POLY1305
{% else %}
# generated 2023-06-13, Mozilla Guideline v5.7, Postfix 3.7.5, OpenSSL 3.0.9, modern configuration
# https://ssl-config.mozilla.org/#server=postfix&version=3.7.5&config=modern&openssl=3.0.9&guideline=5.7

smtpd_tls_mandatory_protocols = !SSLv2, !SSLv3, !TLSv1, !TLSv1.1, !TLSv1.2
smtpd_tls_protocols = !SSLv2, !SSLv3, !TLSv1, !TLSv1.1, !TLSv1.2
{% endif %}

tls_preempt_cipherlist = no
###############################################################################
smtpd_tls_session_cache_database = btree:${data_directory}/smtpd_scache
smtpd_tls_loglevel=1

# -- TLS for outgoing connections
# Use TLS if this is supported by the remote SMTP server, otherwise use plaintext.
{% if relay_port == "465" %}
smtp_tls_wrappermode = yes
smtp_tls_security_level = encrypt
{% else %}
smtp_tls_security_level = may
{% endif %}
smtp_tls_session_cache_database = btree:${data_directory}/smtp_scache
smtp_tls_exclude_ciphers = aNULL, MD5, DES, ADH, RC4, 3DES
smtp_tls_mandatory_ciphers= high
smtp_tls_loglevel=1

# Configure Root CA certificates
# (for example, avoids getting "Untrusted TLS connection established to" messages in logs)
smtpd_tls_CAfile = /etc/ssl/certs/ca-certificates.crt
smtp_tls_CAfile = /etc/ssl/certs/ca-certificates.crt

# See /usr/share/doc/postfix/TLS_README.gz in the postfix-doc package for
# information on enabling SSL in the smtp client.

myhostname = {{ main_domain }}
alias_maps = hash:/etc/aliases
alias_database = hash:/etc/aliases
mydomain = {{ main_domain }}
mydestination = localhost
{% if relay_enabled != "True" %}
relayhost =
{% else %}
relayhost = [{{ relay_host }}]:{{ relay_port }}
{% endif %}
mynetworks = 127.0.0.0/8 [::ffff:127.0.0.0]/104 [::1]/128
mailbox_command = procmail -a "$EXTENSION"
mailbox_size_limit = 0
recipient_delimiter = +
inet_interfaces = all

#### Fit to the maximum message size to 25mb, more than allowed by GMail or Yahoo ####
# /!\ This size is the size of the attachment in base64.
# BASE64_SIZE_IN_BYTE = ORIGINAL_SIZE_IN_MEGABYTE * 1,37 *1024*1024 + 980
# See https://serverfault.com/questions/346895/postfix-mail-size-counting
message_size_limit = 35914708

# Virtual Domains Control
virtual_mailbox_domains = ldap:/etc/postfix/ldap-domains.cf
virtual_mailbox_maps = ldap:/etc/postfix/ldap-accounts.cf,hash:/etc/postfix/app_senders_login_maps
virtual_mailbox_base =
virtual_alias_maps = ldap:/etc/postfix/ldap-aliases.cf,ldap:/etc/postfix/ldap-groups.cf
virtual_alias_domains =
virtual_minimum_uid = 100
virtual_uid_maps = static:vmail
virtual_gid_maps = static:mail
smtpd_sender_login_maps = unionmap:{
   # Regular Yunohost accounts
   ldap:/etc/postfix/ldap-accounts.cf,
   # Extra maps for app system users who need to send emails
   hash:/etc/postfix/app_senders_login_maps }

# Dovecot LDA
virtual_transport = dovecot
dovecot_destination_recipient_limit = 1

# Enable SASL authentication for the smtpd daemon
smtpd_sasl_auth_enable = yes
smtpd_sasl_type = dovecot
smtpd_sasl_path = private/auth
# Fix some outlook's bugs
broken_sasl_auth_clients = yes
# Reject anonymous connections
smtpd_sasl_security_options = noanonymous
smtpd_sasl_local_domain =


# Wait until the RCPT TO command before evaluating restrictions
smtpd_delay_reject = yes

# Basics Restrictions
smtpd_helo_required = yes
strict_rfc821_envelopes = yes

# Requirements for the connecting server
smtpd_client_restrictions =
    permit_mynetworks,
    permit_sasl_authenticated,
    reject_rbl_client bl.spamcop.net,
    reject_rbl_client cbl.abuseat.org,
    reject_rbl_client zen.spamhaus.org,
    permit

# Requirements for the HELO statement
smtpd_helo_restrictions =
    permit_mynetworks,
    permit_sasl_authenticated,
    reject_non_fqdn_hostname,
    reject_invalid_hostname,
    permit

# Requirements for the sender address
smtpd_sender_restrictions =
    reject_sender_login_mismatch,
    permit_mynetworks,
    permit_sasl_authenticated,
    reject_non_fqdn_sender,
    reject_unknown_sender_domain,
    permit

# Requirement for the recipient address
smtpd_recipient_restrictions =
    permit_mynetworks,
    permit_sasl_authenticated,
    reject_non_fqdn_recipient,
    reject_unknown_recipient_domain,
    reject_unauth_destination,
    permit

# SRS
sender_canonical_maps = tcp:localhost:10001
sender_canonical_classes = envelope_sender
recipient_canonical_maps = tcp:localhost:10002
recipient_canonical_classes= envelope_recipient,header_recipient

# Ignore some headers
smtp_header_checks = regexp:/etc/postfix/header_checks

smtp_reply_filter = pcre:/etc/postfix/smtp_reply_filter

# Rmilter
milter_mail_macros = i {mail_addr} {client_addr} {client_name} {auth_authen} {auth_type}
milter_protocol = 6
smtpd_milters = inet:localhost:8891
non_smtpd_milters = inet:localhost:8891

# Skip email without checking if milter has died
milter_default_action = accept

# Avoid to send simultaneously too many emails
smtp_destination_concurrency_limit = 2
default_destination_rate_delay = 5s

# Avoid to be blacklisted due to too many recipient
smtpd_client_recipient_rate_limit=150

# Avoid email adress scanning
# By default it's possible to detect if the email adress exist
# So it's easly possible to scan a server to know which email adress is valid
# and after to send spam
disable_vrfy_command = yes

{% if relay_enabled == "True" %}
# Relay email through an other smtp account
# enable SASL authentication
smtp_sasl_auth_enable = yes
# disallow methods that allow anonymous authentication.
smtp_sasl_security_options = noanonymous
# where to find sasl_passwd
smtp_sasl_password_maps = hash:/etc/postfix/sasl_passwd
{% endif %}

{% if backup_mx_domains != "" %}
# Backup MX (secondary MX)
relay_domains = $mydestination {{backup_mx_domains}}
relay_recipient_maps = hash:/etc/postfix/relay_recipients
maximal_queue_lifetime = 20d
{% endif %}