The number of agreements needed in the email world is significantly higher than what is needed for BGP.
The proponents of "email peering" typically want to switch from the current model (millions of independant email servers) to a different model, with only a few big actors.
I don't know who these proponents are, that you refer to. However, in my earlier message I quite clearly described a model that allows for millions of independent email servers organized in roughly 3 levels of hierarchy and I described how it could be done so that email peering IS NOT LIMITED to a few big actors. The 3 levels that I described were, at the top, intercontinental peering between members of 5 organizations which roughly cover the countries in one continent. I suggest that these 5 organizations should adopt the service boundaries of the RIRs rather than trying to reinvent the wheel. Next, there would be peering between all members in the same continental organization. These members would exchange email with each other under contract terms which clearly lay out the responsibilities of sending operators and receiving operators. Finally, at the lowest level, are organizations who do not see a need to become members of an email peering organization and who exchange email with one or two operators who are members of the peering organization. However, these organizations will also be bound by an explicit contracted AUP because the whole point of this peering hierarchy is to have consistent accountability throughout the entire email architecture. This will not prevent spam, but it will provide operators with the power to shut it off, whenever it occurs. It would be useful to also have the ability to verify initial senders of email messages, however that is not essential for this peering architecture to be useful. Here is a sample scenario. Grandma opens an email with a trojan inside it. The trojan installs itself in her machine and starts sending spam through Grandma's broadband connection. One of the spam recipients informs their ISP that they just received a spam message. Their ISP has a look and agrees that this is indeed spam and they see that this spam is still coming in from a neighboring operator. The ISP follows the contractual procedure and sends an official notification of SPAM to the neighbor. The neighbor follows a similar process and identifies the source as Grandma's ISP. They issue a formal notice to Grandma's ISP and 10 seconds after the notice is received, Grandma's IP connectivity is blocked entirely except for HTPP accesses which are all directed to a walled garden explaining the situation and recommending steps that can be taken to clean up trojans, spyware, viruses, etc. What is missing today? - contracted email SLAs between operators - contracted admin interoperation procedures between operators - contracted SLA and AUP with customers that allows immediate shutdown when malware is detected - organizations which can sort out all the details of the above contracts, etc. If the BGP peering side of the business can sort out all of this stuff, then why can't the email side of the business do the same, or perhaps, do even better? --Michael Dillon