So, after spending three months wheedling management to get us a new server to host a mail group system on, then three days tinkering to get it all set up, guess what I found out?
Mailman, a sophisticated and popular mail list management software package, has a user interface that is an absolute horror. Absolute horror. My 2 year old could do better than that. I can do better than that. I would too, except the developers, as almost all open-source developers are wont to do, spent far more time building an elegant engine than they did an elegant UI. You can't change it without delving deep into a code base written in a language I don't know (Python). Utterly absurd.
But that's what you get when you mess with open source. Unfortunately, this is considered a "best-of-breed" list manager. I'm pretty sure it doesn't get any better.