Akismet is the official plugin for Movable Type that transparently integrates its junk handling capabilities with the Akismet collaborative spam filtering service.
For many people, Akismet will greatly reduce or even completely eliminate the comment and TrackBack spam you get on your sites. If one does happen to get through, simply mark it as Junk and Akismet will learn from the mistake.
This is the official plugin for Movable Type that was developed by Appnel Solutions for Automattic, the people behind the Akismet service.
Movable Type versions: 4.3