I've got some doubts (Score 1)

Meng Wong definately has a point analyzing the current problems with the email system. But I don't think all those changes he sees coming up will affect the SMTP mail system. Default deny and whitelists would break the free-spirit character of the mail network, banning people from communication who are already limited in their freedom of speech. This was also the main point brought up against most of the anti-spam proposals we have seen over the last year or two.

What I think will come is some kind of "trusted mail" protocol, with its own servers and clients apps. Everyone participating will have to register and prove his identity, and there will be measures to prevent people (at least mostly) from forging identities. Just making sure the thief is caught should be enough to scare them off. But this system has to be so strict it won't hit home in a rush. I expect it to be an alternative messaging system for geeks at first, then drifting slowly towards a business-only communications system, until finally it will become an accepted alternative to classical smtp mail.

Once companies see that there is a reliable system that can also be used to reach customers without putting them at risk for phishing attacks, they will happily jump on that train. Of course, there has to be a global registry, but if it works out for domain names and ip addresses, then the community can surely establish something similar for identity verification.

And maybe we also get some bonus addons, like standardized attachment wrapping, unicode character sets in the headers, more detailed header entries and having to implement just one identification protocol between clients and servers.