Postfix

Local mailserver

This example describes the installation of a postfix mailserver that just handles local mail and forwards root's mail to an external account.

Install Postfix:

# apt-get install postfix heirloom-mailx

Postfix Configuration:

Listen to localhost only, in /etc/postfix/main.cf:

smtpd_banner = $myhostname ESMTP $mail_name (Debian/GNU)
biff = no
append_dot_mydomain = no
readme_directory = no

myhostname = server.example.com
alias_maps = hash:/etc/aliases
alias_database = hash:/etc/aliases
myorigin = /etc/mailname
mydestination = server.example.com, localhost.example.com, localhost
mynetworks = 127.0.0.0/8 [::ffff:127.0.0.0]/104 [::1]/128
relayhost = 
mailbox_size_limit = 0
recipient_delimiter = +
inet_interfaces = loopback-only
inet_protocols = ipv4

Restart and verify:

# /etc/init.d/postfix restart
# netstat -tan
tcp        0      0 127.0.0.1:25            0.0.0.0:*               LISTEN

Set mail aliases in /etc/aliases:

root: foo
foo: foo+root@example.net

Update alias database:

# newaliases

Test it:

# mail -s "Testmail" root
This is a test mail.
.
EOT

This should send a testmail to foo+root@example.net.