Racker Hacker Words of wisdom from a server administrator

I’ve used this extremely basic procmail configuration a million times, and it’s a great start for any server configuration. It passes e-mails through spamassassin (if they’re smaller than 256KB) and then filters any e-mail marked as spam to /dev/null:
LOGFILE=/var/log/procmail.log
DROPPRIVS=yes
:0fw
| /usr/bin/spamc
:0
* ^X-Spam-Status: Yes
/dev/null
Of course, you can make this much more complicated with some additional customization.

Enabling submission port support for Postfix is really easy. To have postfix listen on both 25 and 587, be sure that the line starting with submission is uncommented in /etc/postfix/master.cf:
smtp inet n - n [...]