Hy,
this post is not about pentesting, but this weekend I had to move a domain of a friend of mine to my Debian server. After moving the domain I needed also to setup a (IMAP-) mail server. I'm not so good into configuring a whole mailserver system, but I found this really great tutorial:
http://workaround.org/ispmail/squeeze/
It worked just like a charme. And even if you have a problem just look in the comments, there is for sure someone that already had the same problem. If not, look in /var/log/mail.log ;-)
Cheers.
