LISTSERV mailing lists:
"On February 15, 2015, Wizards of the Coast will terminate our LISTSERV system that manages this (and other) mailing lists. We've watched the usage of these mailing lists dwindle due to the rise of other communication platforms, such as forums and social media. Given this decreased usage, we have made the decision that it was time to turn them off."
Back in the day these mailing lists were a valuable forum for discussion of many fan-favorite game worlds including Mystara and Greyhawk. For those folks who like to collect and save every bit of online lore and commentary out there, you'd best start making your archived backups now.
I myself occasionally dabbled in the LISTSERVs in the early 2000's but I never got into them enough that I'd have an attachment to the content in these archives. Part of me would like to sift through them for some interesting content to highlight on Greyhawkery but perhaps like Wizards, it's best to let this one go.