Similar concept, same scaling problems; it just hides the explicit routing from the user (as would any modern "peering" system, presumably).
Then you are presuming wrongly. Nowhere in what I wrote have I suggested any changes in the existing email technology. I am not suggesting that we drop SMTP in favour of your favourite old dusty protocol. I am suggesting that we need a system of accountability for people who run Internet email servers based on contracts and SLAs, i.e. peering agreements. I haven't specified how it would be implemented because I expect that the companies negotiating such agreements would specify this in some kind of operational best-practices document. One way that it COULD be implemented is for people accepting incoming email on port 25 to check a whitelist before accepting email. Only operators who have signed a peering agreement would be on the whitelist. Presumably, the whitelist would be served up by your regional association and they would have some means of relaying queries (or synchronizing their database) with the other 4 regions. Let's face it, people have described a lot of best practices for running SMTP based email services but there has never been a concerted effort to implement these in some methodical way. It has always been a case of preaching to the converted at NANOG or on some lists. And it just does not scale! --Michael Dillon