That's all well and good until said ISP's upstream servers go slow/break/take an age to deliver a message you can deliver from your own host immediately. [It also doesn't scale particularly well]
I don't believe this at all. By going with a whitelist type system that can cache or do cached lookups locally, it wouldn't take any more time to deliver mail than it does today. In fact, it would probably be faster since mail systems would be a lot cleaner not dealing with all the crap that's out there now. I'm not saying that people can't run their own mail servers, certainlly your ISP can register your mail server for you, in their IP space, so that it can be tracked.
I thought I was buying *Internet* access anyway... shouldn't that mean I have the right to talk which hosts I want on which port I want?
Sure it does. But if the remote host says you need to ID yourself as a "trusted source", and they require it, it's not just your right to connect to anyone you want, but the right of the remote server to require that of you. -- Robert Blayzor, BOFH INOC, LLC rblayzor@inoc.net A computer program does what you tell it to do, not what you want it to do.