Mailinglist software recommendations?

["Marcel Hicking" <hicking@du.gtn.com>]

Hi folks

could anyone recommend a mailinglist software for
several small to medium sized mailinglists (say,
from very few to maybe a thousand or so subscribers)?

I would need
a) The mailingslist software (obviously)
b) Some admin web interface for the guys going
to use and feed the lists. Need to be able to add lists,
see and modify subscribers. And, if possible, write and
post mails to the list via the web itnerface, too.
c) A web interface to (un)subscribe to lists (which I
could probably do myself ;-)

Subscribers should not be able to post to the list in
general, but having this optional for each list would
be nice to have.

Is there anythinglike this packaged for Debian?

TIA,
Marcel