mail/claws-mail-bogofilter 4.3.1nb7 NetBSD

The Bogofilter plugin provides anti-spam capabilities for Claws Mail. Bogofilter is a pure Bayesian filter, written in C, which makes it very fast. Claws Mail also provides a SpamAssassin anti-spam plugin, with the same feature set, but more extensive 'spaminess' checks. The Bogofilter plugin features are:

\* Filtering spam when mail is received, moving it to a specific
  folder, or destroying it completely,
\* Learning what is spam and what is ham, in order to better
  filter your mailbox.

Before Bogofilter is able to function effectively, you have to show it a few of your spam emails and a few real emails. You can do that by selecting some messages, right-clicking on them and choosing 'Mark/Mark as spam' or 'Mark/Mark as ham'.