At the risk of finding a brown paper bag bug, I've released the latest version of my mailhacks modules. See my Perl projects page or wait for the Mail::Action 0.30, Mail::SimpleList 0.87, and Mail::TempAddress 0.56 to hit the CPAN.
Tomorrow's project? Test::MockObject::Extends.
(Mini-rant: Mail::Box is huge to pull in just for message handling, but it appears to work. It'd surely be nice if it were split into smaller pieces, though. I don't need IMAP, POP3, mbox, or maildir handling to parse a message.)