Stopping spam by redesigning SMTP from the ground up?

Interesting column by Larry Selzer. Quote:

“Sometimes I look at the Internet and I see so many different ways being used to compromise security that I wonder whether we’d be better off trashing a lot of the existing infrastructure. After all, the Internet was designed to be secure from nuclear attack, not its own users. The whole idea of network security probably never occurred to the designers of the Internet and the main applications that run it.

In my mind, the biggest failure in this regard is SMTP, the dominant mail protocol of the net. Spam is as pervasive as it is because of weaknesses in SMTP. We know how to fix these problems; the problem is that doing so would break existing applications, which means e-mail in general. This is always a bad thing, but it’s not always a deal-killer. I think this is one area where, in the long term, it may make sense to move away from a protocol that has allowed e-mail to get out of control….”.