diff --git a/mail-mta/postfix/Manifest b/mail-mta/postfix/Manifest
index 8d4af371465e7..36ad39abd32af 100644
--- a/mail-mta/postfix/Manifest
+++ b/mail-mta/postfix/Manifest
@@ -1,3 +1,4 @@
 DIST postfix-3.6.1.tar.gz 4748754 BLAKE2B c64d8f4c12cd7cb39bd15c371c20db4aa61b39120b6c078eda7c48c94d65e181b51ac8f74f3231791fc3ad6c0d04f74975f50776f984ffa9b9f8a4c5c99cbade SHA512 6f83a6aa55bd442fe005b35c7470483ff5ba6781121f783b07ef454580354fc5c85d0d5106936810d6bef0f5592937f0863eec3b82e138caac7694e2a3bb7bc3
 DIST postfix-3.6.2.tar.gz 4749530 BLAKE2B 349f3eb2995fe72c89e374a2f95cbb09d4a4f5a5c896e340a2a166ffcb2c498ba514022a59a17d2731807f6dadc03f804a3d4b16127dd2d6addb825558b7ffd6 SHA512 464ce9ec77e637ede91123472a0383b2bfda52102f9e9852c7191016d4fda2e14f302f2db9793887c182688c2a14dde6eeda728523196a627a8028f99555a4d9
+DIST postfix-3.6.3.tar.gz 4750833 BLAKE2B 2a68e0f18227e09c0ce855901503fa83a58805f036f57eff9003102f5933a241e624e5f3f7a7af4f3d89784d95bc0be6ac1d17f30712f61491808ed6a90ce2d3 SHA512 7179aaeeaf27838b867d9a07f9a889d7cd6b7f5053e123caef4dff2820d4df6d5be167effedde6c857b4468966b8449c631e56405e1ac2d589716fb4e3f15e3b
 DIST postfix-3.7-20211030.tar.gz 4769363 BLAKE2B f37e95d83407989965ee898c29372fd70465c449876f5e22277921c8f5deb2e73f4e8abff2aa4bc44e6e9eab3b1854fea0f71df655933d70a78f9b1f7c9c8e2b SHA512 e97383799e2ecfbd8a87d5608d4604cd6ed792da193ee21356c7ed17426e1ca8b03dab0d991c49effd00f478736dde9a28ab83eca555b89cb0820824aef98842
diff --git a/mail-mta/postfix/postfix-3.6.3.ebuild b/mail-mta/postfix/postfix-3.6.3.ebuild
new file mode 100644
index 0000000000000..9fe7bafd66bf6
--- /dev/null
+++ b/mail-mta/postfix/postfix-3.6.3.ebuild
@@ -0,0 +1,290 @@
+# Copyright 1999-2021 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+EAPI=7
+inherit pam systemd toolchain-funcs
+
+MY_PV="${PV/_rc/-RC}"
+MY_SRC="${PN}-${MY_PV}"
+MY_URI="ftp://ftp.porcupine.org/mirrors/postfix-release/official"
+RC_VER="2.7"
+
+DESCRIPTION="A fast and secure drop-in replacement for sendmail"
+HOMEPAGE="http://www.postfix.org/"
+SRC_URI="${MY_URI}/${MY_SRC}.tar.gz"
+
+LICENSE="|| ( IBM EPL-2.0 )"
+SLOT="0"
+KEYWORDS="~alpha ~amd64 ~arm ~arm64 ~hppa ~ia64 ~mips ~ppc ~ppc64 ~s390 ~sparc ~x86"
+IUSE="+berkdb cdb dovecot-sasl +eai ldap ldap-bind lmdb memcached mbox mysql nis pam postgres sasl selinux sqlite ssl"
+
+DEPEND="
+	acct-group/postfix
+	acct-group/postdrop
+	acct-user/postfix
+	>=dev-libs/libpcre-3.4
+	dev-lang/perl
+	berkdb? ( >=sys-libs/db-3.2:* )
+	cdb? ( || ( >=dev-db/tinycdb-0.76 >=dev-db/cdb-0.75-r4 ) )
+	eai? ( dev-libs/icu:= )
+	ldap? ( net-nds/openldap )
+	ldap-bind? ( net-nds/openldap[sasl] )
+	lmdb? ( >=dev-db/lmdb-0.9.11:= )
+	mysql? ( dev-db/mysql-connector-c:0= )
+	nis? ( net-libs/libnsl:= )
+	pam? ( sys-libs/pam )
+	postgres? ( dev-db/postgresql:* )
+	sasl? (  >=dev-libs/cyrus-sasl-2 )
+	sqlite? ( dev-db/sqlite:3 )
+	ssl? ( >=dev-libs/openssl-1.1.1:0= )
+	"
+
+RDEPEND="${DEPEND}
+	memcached? ( net-misc/memcached )
+	net-mail/mailbase
+	!mail-mta/courier
+	!mail-mta/esmtp
+	!mail-mta/exim
+	!mail-mta/msmtp[mta]
+	!mail-mta/netqmail
+	!mail-mta/nullmailer
+	!mail-mta/sendmail
+	!mail-mta/opensmtpd
+	!mail-mta/ssmtp[mta]
+	selinux? ( sec-policy/selinux-postfix )"
+
+REQUIRED_USE="ldap-bind? ( ldap sasl )"
+
+S="${WORKDIR}/${MY_SRC}"
+
+PATCHES=(
+	"${FILESDIR}/${PN}-glibc-2.34.patch"
+)
+
+src_prepare() {
+	default
+	sed -i -e "/^#define ALIAS_DB_MAP/s|:/etc/aliases|:/etc/mail/aliases|" \
+		src/util/sys_defs.h || die "sed failed"
+	# change default paths to better comply with portage standard paths
+	sed -i -e "s:/usr/local/:/usr/:g" conf/master.cf || die "sed failed"
+}
+
+src_configure() {
+	for name in CDB LDAP LMDB MYSQL PCRE PGSQL SDBM SQLITE
+	do
+		local AUXLIBS_${name}=""
+	done
+
+	# Make sure LDFLAGS get passed down to the executables.
+	local mycc="-DHAS_PCRE" mylibs="${LDFLAGS} -ldl"
+	AUXLIBS_PCRE="$(pcre-config --libs)"
+
+	use pam && mylibs="${mylibs} -lpam"
+
+	if use ldap; then
+		mycc="${mycc} -DHAS_LDAP"
+		AUXLIBS_LDAP="-lldap -llber"
+	fi
+
+	if use mysql; then
+		mycc="${mycc} -DHAS_MYSQL $(mysql_config --include)"
+		AUXLIBS_MYSQL="$(mysql_config --libs)"
+	fi
+
+	if use postgres; then
+		mycc="${mycc} -DHAS_PGSQL -I$(pg_config --includedir)"
+		AUXLIBS_PGSQL="-L$(pg_config --libdir) -lpq"
+	fi
+
+	if use sqlite; then
+		mycc="${mycc} -DHAS_SQLITE"
+		AUXLIBS_SQLITE="-lsqlite3 -lpthread"
+	fi
+
+	if use ssl; then
+		mycc="${mycc} -DUSE_TLS"
+		mylibs="${mylibs} -lssl -lcrypto"
+	fi
+
+	if use lmdb; then
+		mycc="${mycc} -DHAS_LMDB"
+		AUXLIBS_LMDB="-llmdb -lpthread"
+	fi
+
+	if ! use eai; then
+		mycc="${mycc} -DNO_EAI"
+	fi
+
+	# broken. and "in other words, not supported" by upstream.
+	# Use inet_protocols setting in main.cf
+	#if ! use ipv6; then
+	#	mycc="${mycc} -DNO_IPV6"
+	#fi
+
+	if use sasl; then
+		if use dovecot-sasl; then
+			# Set dovecot as default.
+			mycc="${mycc} -DDEF_SASL_SERVER=\\\"dovecot\\\""
+		fi
+		if use ldap-bind; then
+			mycc="${mycc} -DUSE_LDAP_SASL"
+		fi
+		mycc="${mycc} -DUSE_SASL_AUTH -DUSE_CYRUS_SASL -I/usr/include/sasl"
+		mylibs="${mylibs} -lsasl2"
+	elif use dovecot-sasl; then
+		mycc="${mycc} -DUSE_SASL_AUTH -DDEF_SERVER_SASL_TYPE=\\\"dovecot\\\""
+	fi
+
+	if ! use nis; then
+		mycc="${mycc} -DNO_NIS"
+	fi
+
+	if ! use berkdb; then
+		mycc="${mycc} -DNO_DB"
+		if use cdb; then
+			# change default hash format from Berkeley DB to cdb
+			mycc="${mycc} -DDEF_DB_TYPE=\\\"cdb\\\""
+		fi
+	fi
+
+	if use cdb; then
+		mycc="${mycc} -DHAS_CDB -I/usr/include/cdb"
+		# Tinycdb is preferred.
+		if has_version dev-db/tinycdb ; then
+			einfo "Building with dev-db/tinycdb"
+			AUXLIBS_CDB="-lcdb"
+		else
+			einfo "Building with dev-db/cdb"
+			CDB_PATH="/usr/$(get_libdir)"
+			for i in cdb.a alloc.a buffer.a unix.a byte.a ; do
+				AUXLIBS_CDB="${AUXLIBS_CDB} ${CDB_PATH}/${i}"
+			done
+		fi
+	fi
+
+	sed -i -e "/^RANLIB/s/ranlib/$(tc-getRANLIB)/g" "${S}"/makedefs
+	sed -i -e "/^AR/s/ar/$(tc-getAR)/g" "${S}"/makedefs
+
+	emake makefiles shared=yes dynamicmaps=no pie=yes \
+		shlib_directory="/usr/$(get_libdir)/postfix/MAIL_VERSION" \
+		DEBUG="" CC="$(tc-getCC)" OPT="${CFLAGS}" CCARGS="${mycc}" AUXLIBS="${mylibs}" \
+		AUXLIBS_CDB="${AUXLIBS_CDB}" AUXLIBS_LDAP="${AUXLIBS_LDAP}" \
+		AUXLIBS_LMDB="${AUXLIBS_LMDB}" AUXLIBS_MYSQL="${AUXLIBS_MYSQL}" \
+		AUXLIBS_PCRE="${AUXLIBS_PCRE}" AUXLIBS_PGSQL="${AUXLIBS_PGSQL}" \
+		AUXLIBS_SQLITE="${AUXLIBS_SQLITE}"
+}
+
+src_install() {
+	LD_LIBRARY_PATH="${S}/lib" \
+	/bin/sh postfix-install \
+		-non-interactive \
+		install_root="${D}" \
+		config_directory="/etc/postfix" \
+		manpage_directory="/usr/share/man" \
+		command_directory="/usr/sbin" \
+		mailq_path="/usr/bin/mailq" \
+		newaliases_path="/usr/bin/newaliases" \
+		sendmail_path="/usr/sbin/sendmail" \
+		|| die "postfix-install failed"
+
+	# Fix spool removal on upgrade
+	rm -Rf "${D}"/var
+	keepdir /var/spool/postfix
+
+	# Install rmail for UUCP, closes bug #19127
+	dobin auxiliary/rmail/rmail
+
+	# Provide another link for legacy FSH
+	dosym ../sbin/sendmail /usr/$(get_libdir)/sendmail
+
+	# Install qshape, posttls-finger and collate and tlstype
+	dobin auxiliary/qshape/qshape.pl
+	doman man/man1/qshape.1
+	dobin bin/posttls-finger
+	doman man/man1/posttls-finger.1
+	dobin auxiliary/collate/collate.pl
+	newdoc auxiliary/collate/README README.collate
+	dobin auxiliary/collate/tlstype.pl
+	dodoc auxiliary/collate/README.tlstype
+
+	# Performance tuning tools and their manuals
+	dosbin bin/smtp-{source,sink} bin/qmqp-{source,sink}
+	doman man/man1/smtp-{source,sink}.1 man/man1/qmqp-{source,sink}.1
+
+	# Set proper permissions on required files/directories
+	keepdir /var/lib/postfix
+	fowners -R postfix:postfix /var/lib/postfix
+	fperms 0750 /var/lib/postfix
+	fowners root:postdrop /usr/sbin/post{drop,queue}
+	fperms 02755 /usr/sbin/post{drop,queue}
+
+	keepdir /etc/postfix
+	keepdir /etc/postfix/postfix-files.d
+	if use mbox; then
+		mypostconf="mail_spool_directory=/var/spool/mail"
+	else
+		mypostconf="home_mailbox=.maildir/"
+	fi
+	LD_LIBRARY_PATH="${S}/lib" \
+	"${D}"/usr/sbin/postconf -c "${D}"/etc/postfix \
+		-e ${mypostconf} || die "postconf failed"
+
+	insinto /etc/postfix
+	newins "${FILESDIR}"/smtp.pass saslpass
+	fperms 600 /etc/postfix/saslpass
+
+	newinitd "${FILESDIR}"/postfix.rc6.${RC_VER} postfix
+	# do not start mysql/postgres unnecessarily - bug #359913
+	use mysql || sed -i -e "s/mysql //" "${D}/etc/init.d/postfix"
+	use postgres || sed -i -e "s/postgresql //" "${D}/etc/init.d/postfix"
+
+	dodoc *README COMPATIBILITY HISTORY PORTING RELEASE_NOTES*
+	mv "${S}"/examples "${D}"/usr/share/doc/${PF}/
+	# postfix set-permissions expects uncompressed man files
+	docompress -x /usr/share/man
+
+	if use pam; then
+		pamd_mimic_system smtp auth account
+	fi
+
+	if use sasl; then
+		insinto /etc/sasl2
+		newins "${FILESDIR}"/smtp.sasl smtpd.conf
+	fi
+
+	# header files
+	insinto /usr/include/postfix
+	doins include/*.h
+
+	if has_version mail-mta/postfix; then
+		# let the sysadmin decide when to change the compatibility_level
+		sed -i -e /^compatibility_level/"s/^/#/" "${D}"/etc/postfix/main.cf || die
+	fi
+
+	systemd_dounit "${FILESDIR}/${PN}.service"
+}
+
+pkg_postinst() {
+	if [[ ! -e /etc/mail/aliases.db ]] ; then
+		ewarn
+		ewarn "You must edit /etc/mail/aliases to suit your needs"
+		ewarn "and then run /usr/bin/newaliases. Postfix will not"
+		ewarn "work correctly without it."
+		ewarn
+	fi
+
+	# check and fix file permissions
+	"${EROOT}"/usr/sbin/postfix set-permissions
+
+	# configure tls
+	if use ssl ; then
+		if "${EROOT}"/usr/sbin/postfix tls all-default-client; then
+			elog "To configure client side TLS settings:"
+			elog "${EROOT}"/usr/sbin/postfix tls enable-client
+		fi
+		if "${EROOT}"/usr/sbin/postfix tls all-default-server; then
+			elog "To configure server side TLS settings:"
+			elog "${EROOT}"/usr/sbin/postfix tls enable-server
+		fi
+	fi
+}