You could do what I’ve been doing and use Message Filters on a regular email instead:
Filter 1: If From does not contain ‘email@example.com’, Delete it and stop.
Filter 2: If Subject does not contain ‘[My Announce List]’, Add ‘[My Announce List]’ to Subject.
Filter 3: If Subject contains ‘[My Announce List]’, Forward it to ‘firstname.lastname@example.org.’
Filter 4: If Subject contains ‘[My Announce List]’, Forward it to ‘email@example.com.’
…and so on.
This can get a little hard to maintain by hand, so if you’re a programmer you might want to use the Dreamhost API for mail commands.
It is a little irritating that Announce Lists don’t have the admin email functionality. It would be much simpler than using the above process or installing PHPList/etc.