After being away at YAPC::Europe for 6 days, I thought I would see how SpamAssassin would fair on my mailbox. Unfortunately the rule tweaking app doesn't quite work (but thats another story) so I only had the basic rules to go on.
I had expected my mail to be around 3,500 messages for the 6 days, as I have regularly been getting over 500 emails a day. Thankfully the script that I wrote a few weeks ago seems to have been doing it's job and the bounce messages have been dwindling. As a consequence I amassed a total of 1,937 messages, of which only 294 were real email. SpamAssassin managed to spot over 1,100 of them, so it faired pretty well, and no false positives either.