I wonder if there exists a community of developers and power administrators of mailing list software, such as Majordomo and MailMan. I happen to both be an administrator of some lists and an author of custom, lightweight mailing list software. Every once in a while there are subtle ways that the standard RFCs can be interpreted, where a community of experts in the field would be great. Is there such a community anywhere?
I highly doubt there is a "Mailing list manager's mailing list" but there is one for Majordomo, MailMan, etc.
From personal observation, mailing list software authors are only slightly less territorial than MTA software authors. I doubt you could even put the authors of Postfix and qmail in the same building, although if that ever happened, I know who I'd like to put $5 on to win.
I subscribed to the procmail mailing list for a long time, and although it was full of procmail users and not necessarily mailing list administrators, they were very knowledgeable about the relevant RFCs and the quirks of various MLMs (often distractingly so). I learned more about internet mail in the real world on that list than anywhere else, although you needed to have a high tolerance for ranting, as MUA and MTA bashing were the rule, not the exception. It might be different now, of course, but that's how it was in 2001-2003 when I was a subscriber.