The functionalities of manitou-mdx can be extended by writing Perl modules that are hooked to manitou-mdx as plugins. A plugin module may be a self-contained piece of code, but more often it's used as an interface to an external program, such as a spam filter or a converter that extracts text from a complex file format. Also, plugins may use external Perl modules from the CPAN archive or other sources.
A plugin for manitou-mdx is generally just a Perl module .pm file.
spamc - Calls spamassassin to score messages and tag them spam or not.
spam_learner - Maintenance plugin that runs sa-learn at regular intervals to feed the spamassassin Bayes database with new legitimate and spam messages. It handles the re-training of the spam filter in a way that requires no other action from the end-user than moving messages to or from the trashcan.
mswordindexer - Pass MS-word .doc attachments on to wvWare, convert them to Unicode text and add their words to the full-text index of the body. This allows the user interface's search engine to retrieve those messages based on the contents of their attachments.
html_indexer - Extracts the text from HTML parts and pass it to the full text indexer to allow subsequent searches inside HTML-only contents.
tnef_decoder - Decodes the TNEF format produced by Outlook and replaces the application/ms-tnef part by the original attached contents.