Mailing List components/software (OT?)

If this is too far off-topic, just ignore and I'll let the thread die... ;o)

We're building our own CMS on the .net platform right now. One feature we'd
like to add down the road is a mailing list system that can connect to our
toolset, so a .net mailing list solution.

Key features we're looking for:

 - Multiple lists/Multiple list admins
 - web based sub/unsub
 - ideally, a way for sub's to manage multiple lists
 - the ability to 'sub' to a page and/or 'section' of the site where any
page/section updates are also broadcast to the list 

I'm sure we could build that, but thought I'd check to see if there was an
off-the-shelf product that would be plug-n-playable into a .net CMS
application.

-Darrel