Moderated mailing lists?

I'm looking for a good way to run a moderated mailing list. I've used EZMLM in the past. Is that available on Dreamhost?

Things I'm looking for:

1) Closed list -- only admins can subscribe or unsubscribe addresses

2) Only people on the list can send to it.

3) All messages must be approved by an admin

4) It would be great if the subscription list could be managed using unix command-line tools (i.e. just have a file of addresses)

I looked at the "Announcement list" and "Discussion list" options in the control panel, but unless I missed something, those don't include any moderation functionality.

The discussion list uses gnu mailman on the backend:

http://www.gnu.org/software/mailman/mailman-admin/index.html

discussion lists are only available with full hosting.

Ah, cool. It wasn't obvious from the web panel description.