Yesterday, I spent a reasonable amount of time looking for old mudding related mailing lists. After finding the links, I'd go to their primarily mailman-based pages in the Internet Archive, and look at their archives. Almost all of them lacked accessible archives. About the only one I found archives for, was the Lima Bean mudlib, and even then it was their later years.
Now back when I was trying to piece together the MUD-Dev mailing list, Davion offered a dump of his inbox. And so we now have a pretty complete archive of the MUD-Dev mailing list.
So the requests start here:
Do you know of old MUD mailing lists, including old now not working links, which the Internet Archive can be trawled for?
Do you have mailboxes full of emails from old MUD mailing lists, that you can extract and offer?
Does anyone know George Reese and can ask him for the imaginary.com mailman archives?
I've placed backups of the DGD list (still active) and MUD-Dev2 on my web site.
Yeah, Google's "ownership" of usenet archives has pissed me off. Google has repeatedly kicked me off browsing the archives because it thinks I'm a bot, because I apparently click and browse too fast. Prior to that, I had thought of programming a web reader to extract them, but I suspect it might have to run a year or so to build.
You could also look through Yahoo Groups. They don't seem to be used much for muds these days, but they were used in the past, and the archives are still available. I used to have one for Last City, and still belong to another for GodWars Apocalypse. Neither have many posts, but there may be other groups that do.