Perhaps 'network.protocol-handler.expose.mailto - true' should be either included as an option in the Edit|Preferences|Mail & Newsgroups or Edit|Preferences|Browser?
If at all only in the former, it's about MailNews, not the browser component. You may file an enhancement bug for that. :-)
This should probably be accompanied by a short Help entry that states that this only works if SeaMonkey is *not* set as the system's default mail application.
Greetings, Jens -- Jens Hatlak <http://jens.hatlak.de/> SeaMonkey Trunk Tracker <http://smtt.blogspot.com/> _______________________________________________ support-seamonkey mailing list firstname.lastname@example.org https://lists.mozilla.org/listinfo/support-seamonkey