I am switching over to Zabbix it just works better then Zenoss for me. During the process I added in templates for postfix. Those are outlined here.

I just upgraded from etch to lenny and recursion support was removed from the defaults. So I had to make a few changes to bring it back in. Here is the change I needed to make.

Edit

http://www.debianhelp.co.uk/mailman.htm

#apt-get install mailman

This will install the latest version of mailman

after installation of postfix you need to do the following things