I am subscribed to several specific interest email lists. The information I get there is typically much better than what I find online.
Do you also prefer email lists over a moderated newsgroup? If so, why?
OTOH your own moderation by just ignoring certain senders may be relatively efficient even if nobody actually controls the list server, and the whole thing is just a bunch of peer-to-peer messages with CC large headers.
The other is banning members if they misbehave.
Neither approach is foolproof, and ultimately it's up to the list members to ignore any messages they don't like. One difference with online forums is that it's not possible to recall or delete a message after it's been sent out.