Of course, there's already one application-level messaging protocol that relies extensively on arranged peerings: Usenet. Usenet doesn't rely on a *full* N-way mesh of arranged peerings, it relies instead on a core of fairly well interconnected "backbone" or "core" news sites who've agreed to do feeds with each other, as well as to feed downstream "leaf nodes" (either on a for-fee commercial basis, or gratis as part of a regional consortia or whatever). To receive traffic or originate traffic, a leaf node doesn't need to peer with every other news server, it just needs to do feeds with a couple of upstream core sites to insure that it has reasonable coverage and redundancy. Spam isn't much of a problem on Usenet anymore because peers who tend to have spam issues tend to clean them up or get depeered or shunned... There's no reason why one couldn't build a comparable model for mail, with the SMTP speciality service provider offering "SMTP transit" to a base of trusted customers. This comparatively small number of SMTP speciality provider would then maintain good relations ("peerings") with the comparatively small number of major ISPs. Oh wait -- there are a variety of folks who are already specializing in doing that sort of thing -- it's just that most folks don't need to buy that sort of service (yet). Regards, Joe St Sauver (joe@uoregon.edu) University of Oregon Computing Center