I just stumbled across DADA mail this past month. It is really really really awesome and written in Perl!

http://dadamail.org/

My mailing list finally grew to more than 100 people and keeping track of who subscribed and what email they wanted had started to take more time than writting the weekly email that I send. So far I've used it to send 3 emails and all the headaches of keeping track of bounces and unsubs and new subs has been taken off my hands. I highly recommend it.

It is also written in Perl so you can hack on it if you really need to.

For an announcement list (no discussion) it is perfect. I just unziped the files, and followed a few easy instructions for setting it up (make sure you encrypt the password), and I was sending out email.

Words can't express how happy I am with it.