authenticated *and subject to access control with a default deny posture * The access control is the key. J random grifter cannot send Alice spam BECAUSE SHE HAS NOT AUTHORIZED HIM TO SEND MESSAGES TO HER.
I have to say I'm surprised to see this ancient chestnut reappearing. For about 30 years people have been reinventing this idea, trying to turn the spam problem into the introduction problem, and only accepting mail from people who've been introduced. Which might work except that the introduction problem is harder than the spam problem and as people have pointed out, it is not a bug that you can send email to people you haven't written to before.
If each person maintains her own list of correspndents and authorization tokens, that's Zoemail, described in US patent 5,930,479 which was filed in 1996. If an external authority decides who gets to be introduced, that's Facebook.
For a particularly bad version of this idea, take a look at the original version of Boxbe, in which you could charge people to send you mail. It died from unrelated patent problems but it was a big hit among the pudit class who imagined that they were so important that people would pay them to read messages, and that those messages would nonetheless be worth reading.
Regards, John Levine, johnl@xxxxxxxxx, Taughannock Networks, Trumansburg NY Please consider the environment before reading this e-mail. https://jl.ly
