I don't think that's the problem with these plans. Imagine that email didn't exist, and you were designing it from scratch. There are many easy solutions to th

I don't think that's the problem with these plans. Imagine that email didn't exist, and you were designing it from scratch. There are many easy solutions to the spam problem if you start with a clean slate. The problem is that nobody would ever adopt email today if it was new. More recent decentralized solutions haven't failed because of spam, but through lack of adoption.