====== Configure postfix ======

  * Three files to edit/create in /etc/postfix - master.cf, main.cf, transport
  * Also check/modify /etc/mailname file
  * The examples below are using //nixgate// for a machine name & //webman// as a user name.
    * Change your machine & user names appropriate to your system.

==== After editing files ====
  * as root convert the transport text file to a database file format.
<code bash>
postmap /etc/postfix/transport
</code>
  * After editing master.cf or main.cf should restart postfix as root
<code bash>
# systemd way
systemctl restart postfix
# System V init way
/etc/init.d/postfix restart
</code>
===== Example master.cf =====
  * Add these 2 lines before maildrop entry
  * Note the 2 spaces at the beginning of the second line are significant.
<file>
wl2k      unix  -       n       n       -       1      pipe
  flags=XFRhu user=webman argv=/usr/local/libexec/mail.wl2k -m
</file>

===== Example main.cf =====

  * Check that file /etc/mailname exists
<file>
#myorigin = /etc/mailname

smtpd_banner = $myhostname ESMTP $mail_name (Debian/GNU)
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 parameters
smtpd_tls_cert_file=/etc/ssl/certs/ssl-cert-snakeoil.pem
smtpd_tls_key_file=/etc/ssl/private/ssl-cert-snakeoil.key
smtpd_use_tls=yes
smtpd_tls_session_cache_database = btree:${data_directory}/smtpd_scache
smtp_tls_session_cache_database = btree:${data_directory}/smtp_scache

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

myhostname = nixgate
alias_maps = hash:/etc/aliases
alias_database = hash:/etc/aliases
mydestination = nixgate, nixgate.localnet, localhost.localnet, localhost
relayhost = 
mynetworks = 127.0.0.0/8 [::ffff:127.0.0.0]/104 [::1]/128

mailbox_size_limit = 0
recipient_delimiter = +
inet_interfaces = all
#home_mailbox = Mail/

# Added for paclink-unix config
transport_maps = hash:/etc/postfix/transport
</file>
  * When starting postfix if it complains about IPV6 then do the following:
    * Add this line to main.cf
<file>
inet_protocols = ipv4
</file>
  * Change the //mynetworks// line in main.cf to:
<file>
mynetworks = 127.0.0.0/8 
</file>

  *  Now [[plu:install_postfix#after_editing_files | restart Postfix]]
  * [[http://www.postfix.org/IPV6_README.html | postfix IPV6 reference]]
===== Example transport file =====
  * This is a very simple example that assumes that the machine that postfix is installed on is **only** concerned with winlink mail.
  * In the example below //nixgate// is a host machine name.
<file>
#
localhost :
nixgate             local:
nixgate.localnet    local:
nixgate.localhost   local:
*         wl2k:localhost
</file>
  * whenever you edit the transport table as root execute the command:
<code bash>
   postmap /etc/postfix/transport
</code>
===== Example /etc/mailname file =====
<file>
nixgate.localnet
</file>

===== Config aliases file to receive mail addressed to root =====

  * edit // /etc/aliases// to get all mail the system will send to root & postmaster
    * After editing run this as root:
<code bash>
newaliases
</code>
  * Verify by checking for the creation of the ///etc/aliases.db// file
<code bash>
ls -salt /etc/aliases*
</code>
==== Example /etc/aliases file ====
<file>
# /etc/aliases
root: webman
mailer-daemon: postmaster
postmaster: webman
nobody: root
hostmaster: root
usenet: root
news: root
webmaster: root
www: root
ftp: root
abuse: root
noc: root
security: root
</file>