Because that would require providers to act like professionals, join an Internet Mail Services Association, agree on policies for mail exchange, and require mail peering agreements in order to enable port 25 access to anyone.
Nice in theory, but I don't think it would scale. In essence you are asking for a return to the UUCP model, where if you wanted to send mail on the network you had to have a deal with someone.
No, I am not suggesting a return to the UUCP model. If I was then I would have said that. I am suggesting that we apply the lessons learned from the BGP peering model. The BGP peering model evolved over many years of people hashing out and modifying many bilateral peering agreements. I don't think we need to do this with email, because we the larger email providers can all sit down and together and based on the BGP experience, they can come up with a standard multilateral agreement that will suit most people. Or, more likely, two multilateral agreements. One for members of the email peering core, and the other for non-core operators. The reason this needs to be done in an association, in public, is because email is not BGP. BGP is an arcane piece of technology which does an arcane job in interconnecting networks. There is no significant public interest in BGP. Email, on the other hand, is an end user service and it is abundantly clear that the end users of the world are FED UP with the inability of Internet email providers to maintain and improve the quality of the service. Every year for the past 10 years the quality of Internet email has degraded. And while other services like instant messaging can take up some of the slack, they cannot fully replace a store and foreward email system.
But, every time someone tries a blanket block of (for instance) China, or even appears to do so, there's a huge outcry. If you create an organization to do that, you'll not only have an outcry, you'll have a target for legal action (restraint of trade?).
There you go again, just like everyone else. You assume that the problem is somebody else and we just need to shoot that somebody else with big guns. Well, I have news for you. I HAVE SEEN THE ENEMY AND HE IS US! The problem is a fundamental shoddiness in the email services architecture which is compounded by a fundamental shoddiness in email service operations. Bandaid solutions abound. The whole thing is made out of bits of string and sealing wax. I recommend that you read Dave Crocker's draft on Internet email architecture. http://www.bbiw.net/specifications/draft-crocker-email-arch-03.html In order to understand what I am getting at you have to begin looking at the problem from a high level, not down in the greasy gearboxes. Dave's draft can be a bit inscrutable, but he is at least trying to document the overall architecture so that we can talk clearly about how to manage it in a way that provides a high quality email service to the end user. --Michael Dillon