> From: "Perry E. Metzger" <perry@piermont.com> > ... > I use a very large variety of techniques to block spam, and I'm > something like 95% successful. The 5% is starting to kill me, and > making things substantially more successful than that is likely not > possible without blocking lots of legitimate mail. > ... If you're are getting only 95% with a large variety of filters, then you should throw them all out and start over. Two independent 80% filters should be good for 96%. There is no single silver bullet for spam, but there are things that help a lot. There are many tactics that do better than 5% false negatives (i.e. filter 95% of spam), with varying false positives for various individual situations. My personal combination of filters (which would almost certainly *not* be appropriate for your situation) does better than 99% (i.e. fewer than 1% false negatives) with fewer than 1 false positive per month (i.e. fewer than 0.1% false positives). Perhaps the most important aspect of spam filtering is it needs minimal participation from the mailbox owner. To do better than about 60% false negatives with fewer then 10% false positives, the mailbox owner must at least be willing to maintain personal white and/or blacklists. This fact is sort of the obverse of another fact, that if more than 1% of spam targets complained about spam to ISPs (as opposed to the fewer than 0.01% in practice), then spam would never have been a problem. Vernon Schryver vjs@rhyolite.com