Bogofilter is a Bayesian spam filter. In its normal mode of operation, it takes an email message or other text on standard input, does a statistical check against lists of "good" and "bad" words, and returns a status code indicating whether or not the message is spam. Bogofilter is designed with fast algorithms (including Berkeley DB system), coded directly in C, and tuned for speed, so it can be used for production by sites that process a lot of mail. Bogofilter can be built with different database backends. Default is Berkeley DB available in Slackware (db44 and older versions). You can use sqlite3 instead, available from slackbuilds.org, by setting the DATABASE environment variable. Once the package is installed, there is good documentation available in the standard location.