Many large organizations already have already, in a case by case way, set up private mail peering with others they exchange large volumes of mail with. This "trusted traffic" is often able to bypass the expense and delay of the spam-filter farm, making the cost and hassle of a parallel mail infrastructure worthwhile to them, and everyone is happy.
Sounds good.
I don't think what you have been talking about so far will work, and I don't think I'm alone in that.
That's strange because you just finished describing how SOME companies are already engaging in email peering on a piecemeal basis. And how these companies ARE finding this to be beneficial in reducing costs. So please explain why my suggestion about widespread email peering agreements won't work? And please don't suggest that webs of trust are not scalable. Given the techniques of scaling that we have in the 21st century, I simply don't believe that. --Michael Dillon