includes set-up of redirection from TCP port 26 to TCP port 587 (alternate

  SMTP submission port to work around common network blocks).

* For user submission (SMTP), users must connect and authenticate over TCP

  port 587.

* TLS configuration is hardened for Postfix on submission port 587, allowing

  only TLSv1.2 and PFS ciphers. No TLS hardening is performed on port 25 in

  order to maintain maximum interoperability.

  your choice. When doing so, use port 587 for SMTP. Port 25 is reserved for

  unauthenticated server-to-server mail deliveries. TLS has also been hardened

  on port 587 to allow only TLSv1.2 and PFS ciphers.

        # SMTP for server communication.

        # SMTP for client submission (with alternative port)

        proto tcp dport 587 ACCEPT;

        proto tcp dport 26 REDIRECT to-ports 587;

#

# Postfix master process configuration file.  For details on the format

# of the file, see the master(5) manual page (command: "man 5 master" or

# on-line: http://www.postfix.org/master.5.html).

#

# Do not forget to execute "postfix reload" after editing this file.

#

# ==========================================================================

# service type  private unpriv  chroot  wakeup  maxproc command + args

#               (yes)   (yes)   (yes)   (never) (100)

# ==========================================================================

smtp      inet  n       -       -       -       -       smtpd

#smtp      inet  n       -       -       -       1       postscreen

#smtpd     pass  -       -       -       -       -       smtpd

#dnsblog   unix  -       -       -       -       0       dnsblog

#tlsproxy  unix  -       -       -       -       0       tlsproxy

#submission inet n       -       -       -       -       smtpd

#  -o syslog_name=postfix/submission

#  -o smtpd_tls_security_level=encrypt

#  -o smtpd_sasl_auth_enable=yes

#  -o smtpd_reject_unlisted_recipient=no

#  -o smtpd_client_restrictions=$mua_client_restrictions

#  -o smtpd_helo_restrictions=$mua_helo_restrictions

#  -o smtpd_sender_restrictions=$mua_sender_restrictions

#  -o smtpd_recipient_restrictions=

#  -o smtpd_relay_restrictions=permit_sasl_authenticated,reject

#  -o milter_macro_daemon_name=ORIGINATING

#smtps     inet  n       -       -       -       -       smtpd

#  -o syslog_name=postfix/smtps

#  -o smtpd_tls_wrappermode=yes

#  -o smtpd_sasl_auth_enable=yes

#  -o smtpd_reject_unlisted_recipient=no

#  -o smtpd_client_restrictions=$mua_client_restrictions

#  -o smtpd_helo_restrictions=$mua_helo_restrictions

#  -o smtpd_sender_restrictions=$mua_sender_restrictions

#  -o smtpd_recipient_restrictions=

#  -o smtpd_relay_restrictions=permit_sasl_authenticated,reject

#  -o milter_macro_daemon_name=ORIGINATING

#628       inet  n       -       -       -       -       qmqpd

pickup    unix  n       -       -       60      1       pickup

cleanup   unix  n       -       -       -       0       cleanup

qmgr      unix  n       -       n       300     1       qmgr

#qmgr     unix  n       -       n       300     1       oqmgr

tlsmgr    unix  -       -       -       1000?   1       tlsmgr

rewrite   unix  -       -       -       -       -       trivial-rewrite

bounce    unix  -       -       -       -       0       bounce

defer     unix  -       -       -       -       0       bounce

trace     unix  -       -       -       -       0       bounce

verify    unix  -       -       -       -       1       verify

flush     unix  n       -       -       1000?   0       flush

proxymap  unix  -       -       n       -       -       proxymap

proxywrite unix -       -       n       -       1       proxymap

smtp      unix  -       -       -       -       -       smtp

relay     unix  -       -       -       -       -       smtp

#       -o smtp_helo_timeout=5 -o smtp_connect_timeout=5

showq     unix  n       -       -       -       -       showq

error     unix  -       -       -       -       -       error

retry     unix  -       -       -       -       -       error

discard   unix  -       -       -       -       -       discard

local     unix  -       n       n       -       -       local

virtual   unix  -       n       n       -       -       virtual

lmtp      unix  -       -       -       -       -       lmtp

anvil     unix  -       -       -       -       1       anvil

scache    unix  -       -       -       -       1       scache

#

# ====================================================================

# Interfaces to non-Postfix software. Be sure to examine the manual

# pages of the non-Postfix software to find out what options it wants.

#

# Many of the following services use the Postfix pipe(8) delivery

# agent.  See the pipe(8) man page for information about ${recipient}

# and other message envelope options.

# ====================================================================

#

# maildrop. See the Postfix MAILDROP_README file for details.

# Also specify in main.cf: maildrop_destination_recipient_limit=1

#

maildrop  unix  -       n       n       -       -       pipe

  flags=DRhu user=vmail argv=/usr/bin/maildrop -d ${recipient}

#

# ====================================================================

#

# Recent Cyrus versions can use the existing "lmtp" master.cf entry.

#

# Specify in cyrus.conf:

#   lmtp    cmd="lmtpd -a" listen="localhost:lmtp" proto=tcp4

#

# Specify in main.cf one or more of the following:

#  mailbox_transport = lmtp:inet:localhost

#  virtual_transport = lmtp:inet:localhost

#

# ====================================================================

#

# Cyrus 2.1.5 (Amos Gouaux)

# Also specify in main.cf: cyrus_destination_recipient_limit=1

#

#cyrus     unix  -       n       n       -       -       pipe

#  user=cyrus argv=/cyrus/bin/deliver -e -r ${sender} -m ${extension} ${user}

#

# ====================================================================

# Old example of delivery via Cyrus.

#

#old-cyrus unix  -       n       n       -       -       pipe

#  flags=R user=cyrus argv=/cyrus/bin/deliver -e -m ${extension} ${user}

#

# ====================================================================

#

# See the Postfix UUCP_README file for configuration details.

#

uucp      unix  -       n       n       -       -       pipe

  flags=Fqhu user=uucp argv=uux -r -n -z -a$sender - $nexthop!rmail ($recipient)

#

# Other external delivery methods.

#

ifmail    unix  -       n       n       -       -       pipe

  flags=F user=ftn argv=/usr/lib/ifmail/ifmail -r $nexthop ($recipient)

bsmtp     unix  -       n       n       -       -       pipe

  flags=Fq. user=bsmtp argv=/usr/lib/bsmtp/bsmtp -t$nexthop -f$sender $recipient

scalemail-backend unix	-	n	n	-	2	pipe

  flags=R user=scalemail argv=/usr/lib/scalemail/bin/scalemail-store ${nexthop} ${user} ${extension}

mailman   unix  -       n       n       -       -       pipe

  flags=FR user=list argv=/usr/lib/mailman/bin/postfix-to-mailman.py

  ${nexthop} ${user}

# Delivery via Dovecot.

dovecot   unix  -       n       n       -       -       pipe

  flags=DRhu user=vmail:vmail argv=/usr/lib/dovecot/dovecot-lda -f ${sender} -d ${recipient}

# Submission port with hardened TLS configuration.

submission inet n       -       -       -       -       smtpd

  -o smtpd_sasl_auth_enable=yes

  -o smtpd_tls_security_level=encrypt

  -o smtpd_recipient_restrictions=permit_sasl_authenticated,reject

  -o smtpd_tls_mandatory_protocols=TLSv1.2

  -o smtpd_tls_mandatory_ciphers=high

  -o tls_high_cipherlist=DHE-RSA-AES128-GCM-SHA256:DHE-RSA-AES128-SHA256:DHE-RSA-AES256-GCM-SHA384:DHE-RSA-AES256-SHA256:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-SHA256:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-SHA384:!aNULL:!MD5:!EXPORT

  -o syslog_name=postfix/submission

- name: Deploy Postifx master process configuration

  copy: src="master.cf" dest="/etc/postfix/master.cf"

        owner=root group=root mode=644

# SMTP authentication configured, but disabled by default (for server-to-server

# communication). Users should connect via submission port instead to be able to

# authenticate.

smtpd_sasl_auth_enable = no