Giovanni Andreani wrote: > >I was wondering if SpamSieve works filtering messages before PowerMail does. >For example, let's say I've created a filter where Mr. White's mails are >considered as spam and therefore immediately deleted. Once SpamSieve is >trained to recognize the same incoming messages as spam is it going to >act before PowerMail's filters and, if so, is there any sense in keeping >these filters active? >
SpamSieve is actually invoked via the SpamSieve:evaluate and SpamSieve: actions filters, which you can place anywhere you want in your filter list. One reason you might want to keep your own filters and apply them before SpamSieve is that they can reduce the number of messages you need to check for false positives. As a Bayesian filter, SpamSieve cannot guarantee that it will not declare a valid message to be spam (a false positive), so you need to check messages that it has declared to be spam for false positives and mark them as good so it can learn. As I receive several hundred messages per day, of which 90% are spam, I would spend way too much time checking them all for false positives. Instead, I have my own set of filters that find messages that for one reason or another I know are spam (e.g. they are addressed to my ISP login rather than my domain). Then I let SpamSieve have a crack at the rest, then I delete those that SpamSieve gave a spam rating higher than 90%, under the presumption that no false positives will look quite that much like spam (this may not be strictly true, but so far I'm not aware of any exceptions). With this system I don't need to even glance at more than one or two dozen potential false positives, while filtering out on the order of 200 spams, per day. At this point SpamSieve is so well trained that its accuracy is now running at 99.0%. I've had one false positive is many months, and only one or two false negatives (spams that SpamSieve thinks are real mail), every few weeks. I figure I'm doing about as well as can be expected until ISP start charging postage, as this is th -- Raúl Vera Director Orbit 3 Pty Ltd 8 Coneill Place NSW 2037 Australia http://orbit3.com
