I did some work for this guys a few years who spammed them like crazy (i didn't do the spamming, just saw results). He got alot of bad rep for that tho.
Treat mailing lists, newsgroups, and forums as if they are communities. Become one with the community by actually contributing as a member of that community. Once you are part of it, they will welcome your links...till then you are a spammer that can expect deleted posts, flaming, and sometimes DDOS attacks.
You still haven't, which is why I did... Though, the posters above are correct. They likely will not count (for PR, SERPS, and the like) unless archived or reposted to the internet. They can generate traffic though.
Well yeah thats what I mean, if you contribute to a list serv (which is very easy to do) it will get archived to the net! They always get archived to the net! The question is, how long does it take to get archived? Anyone know?