MLM's in general are discussed on list-managers@greatcircle.com; to subscribe, write "sub list-managers YourAddress" in the body of a message to majordomo@greatcircle.com.
On USENET, comp.mail.list-admin.software and its sibling c.m.l.policy will probably interest you. Both get fairly low traffic and, for USENET at least, fairly low noise. You will also probably enjoy comp.mail.misc and, if your system uses sendmail, comp.mail.sendmail.
MLM functions overlap with those of archive servers, though no single package is really excellent at both jobs. If archive service is a large part of your needs, you should also read Piero Serini's "Mail Archive Server Software List," at <ftp://ftp.uu.net/usenet/news.answers/mail/archive-servers/faq>.