spam - what spam?
There's a simple solution - move to a mail server using spam assassin - we have about 10 users on our own domain, hosted in-house with spam assassin scanning everything coming in, and we each get maybe two to three spam emails per day in our in-boxes - and about 200-300 pieces of junk in the spam folder. We run AV software on the mail server (around 10-30 per day) and don't bother with running individual packages on the desktops.
Life is sweet.