Mahogany can load plugin modules at runtime to extend its functionality. Currently we are working on plugins to supply PGP/GPG encryption support and a scoring engine for sorting mailfolder listings. A plugin to use IBM's ViaVoice will be started work on as soon as the Debian/Linux ``Potato'' release becomes stable.
Generally, if you want to write an extension for Mahogany without using Python (which we hope to turn into a plugin, too, soon), you can do that very easily by writing it as a plugin module. Get in touch with the developers and we will show you how to do so.