Linux Journal: An Easy Way to Avoid Spam Oct 21, 2003, 13 :00 UTC (9 Talkback[s]) (12517 reads) (Other stories by Cezary M. Kruk)
"Spam has become a real problem these days. The more people who know your e-mail address, the more unwanted pieces of mail you receive. If you used your e-mail to register on some Web sites or publish a few articles in the newsgroup, you probably started to receive more unwanted messages than welcome ones. Fortunately, the users of Linux and other open-source systems have written a lot of good anti-spam filters. You can find dozens of these programs on GNU.org and Freshmeat. The anti-spam software may be sophisticated or simple, easy or difficult to use, more or less effective. Amidst the larger well-known projects, there is SpamAssassin, written by Justin Mason, and bogofilter, a Bayesian filter written by Eric S. Raymond, and others.
"Testmail, the filter discussed in this article, is a Perl filter of average size and moderate complexity. It checks e-mail messages available at the POP3 server, filters them according to defined rules and, depending on the selected method, sends messages to the local mailbox or removes them from the server. Testmail requires the Perl libnet, Net-Ping and Socket modules..."
