Desperate for a POP monitor with bounce options

We have just got rid of almost all the Windoze boxes in our office and changed them for shiny new i-Macs (now that they have a 'real' OS!).

We monitor over 70 email addresses and are plagued by ridiculous amounts of spam; on the MS boxes we used Mailwasher Pro which gave us the option of auto deletion/bounce on all emails which had been marked as bad by the excellent learning rules of the software. A simple click to process and only genuine emails came into our inboxes.

I have searched for almost a week now and unless I'm getting particularly myopic in my advancing years, i cannot find anything similar for our Macs.

Found several which makes us mark emails individually and then process, but none have the bounce facility. We get over 400 emails a day usually so it's pretty important for us to have something which works quickly and efficiently.

Any ideas would be most gratefully received (except using Parallels - we're right off Windows!).

Cheers

Bouncing does absolutely no good, as spammers are using faked addresses anyway.

I think SpamAssassin is held in pretty high regard for what you're looking for, as is Spamsieve and Purify, and you can also look at SpamCop (which does ISP reporting).

Thanks Chas

We already use SpamAssassin server side on all our mail servers but we only configure it to mark potential spam as spam - we don't use it to delete or bounce (RFCs don't recommend this apparently).

We have accounts with SpamCop (as well as being a part of ProjectHoneypot) and what we liked about mailwasher was that after it had learned what was spam and what was not, a single click deleted, bounced and reported spam. With the amount we get, that's an important element for us.

I take your point about bouncing (especially as some of the spam is spoofed to come from some of our own addresses) - I guess it's a comfort thing really.

We looked at the Sieve but unless I missed it, it still looks like we have to delete each one individually - might just as well write rules in our mail clients and do that there.

We'll take a look at the other one you mentioned and see if that fits the bill. If not, I guess we'll just have to wait for Firetrust to port theirs to OS X.

Cheers.