As usual, marketing guru Seth Godin has something useful and interesting to say, in this case about his disappointment with spam filters that block his legitimate mail (both mail he was supposed to receive, and mail he had sent to others).
“Stopping spam is a worthless endeavor when you also stop non-spam,” he writes.
Hear hear! I wholeheartedly agree, and this is Commtouch’s philosophy. False positives are much much much much worse than false negatives. If an anti-spam solution is promising 100% detection (unless it’s challenge-response, and yeah, it’s easy to provide 100% when you just block pretty much everything), I would recommend regularly reviewing your quarantine with a fine-tooth comb, and see if you’re not missing some important email messages from time to time. Of course, all that time spent nitpicking your quarantine pretty much uses up the supposed productivity you gained with your super-duper-overblocking spam filter, so… if you find yourself doing it too often it may be time to switch to a better anti-spam engine.