[Techtalk] Spam filtering Mailman..

[agoats]

Is there a way to do spam filtering before mailman? 

We're using Mailman 2.1.6 and I'm being inundated with reports of posts
by non-members, bounces etc for all manner of junk. Half my e-mails at
home are these bounces by spam. 

I've let it run for a few days without clearing out the non-member posts
and I've found that the reported sender(s) send to almost every list
(they don't send to all of them) and do so multiple times. Each poster
will send several different spam types: porn, find a date, casinos,
drugs, 75% off Microsoft and BSA products...

Suggestions?

Alvin