Interesting chain of events... if no peers and Mail-via= Distribute, then the mapping is pretty obvious (all of the list is in one place). If peers, but no Distribute, it's not necessarily optimal distribution. If peers and Mail-via= Distribute (is that valid?) it would do separate distributes for the various peers (?). Subscriptions would be routed based on peers, but the distribution might come from somewhere else. Thus, it would appear that the whole 'Peers=' business would primarily be for purposes of subscription and list submissions. It's semi-irrelevant to the distribution, but could get tacky if it includes peers in the distribution; there's a loop possibility hiding in there somewhere.