Bogofilter is a trainable email spam detector.

Bogofilter takes an email message or other text on standard input, parses it
into words, does a statistical check against databases of "good" and "bad"
words, and returns a status code indicating whether or not the message is spam.
Bogofilter decodes base64 or quoted-printable encoded texts and ignores non-text
attachments and HTML comments.

The supported database backends are LMDB, Kyoto Cabinet and SQLite3.
The upstream version would theoretically also support QDBM and
Tokyo Cabinet, but these are not currently available as FreeBSD ports.
Berkeley DB support is being phased out.
