I use MailWasher Pro 4.1

No problems at all and it works great with avast!

Spamkiller is also good one, but MacLover just reported some problems with that software ( link: http://forum.avast.com/index.php?board=2;action=display;threadid=5232 )…

My advice: stick to MailWasher, you can’t go wrong.

Greetz !