There is someone's body_checks file available for postfix users to help squash the MyDoom virus (thanks again microsoft!). You can put this into your postfix setup by adding the following line to main.cf:
body_checks = regexp:/etc/postfix/body_checkswith the body_checks file being something like what is posted in the link. In theory it should work :)
Anyone know of a good integrated virus checker for postfix like qmail has?
I've added some body_checks onto the ufies.org mail mail system and it's catching stuff already, which is good. If you're losing mail let me know though :)
Some good procmail magic is also available here.