Slamming Spam: A Guide for System Administrators

Efficacy and Attacks

One author’s appreciation of CRM114 has been unbounded. It catches more than 99% of spam, thus freeing the mailbox for its intended purpose. However, it has not quite been perfect. CRM114 (and presumably any well-implemented Bayesian filter) will either pass a little spam through or block the occasional legitimate email as “apparent spam.” In the 21st century, however, the idea that “The spam filter ate your message” has gained much more respect than “My dog ate my homework” ever did!

When a spam message sneaks through, the filter needs additional training. A small program can easily add a single message to the spam mail database.

False positives are another problem. In order to keep statistics, one author skims all 400 ...