> Email should have always been a bidirectional address, representing the relationship between the sender and receiver, and not a wide open receiver for anybody who happens to have your address.

That does seem beneficial for the most part, but do you have ideas about how to handle the use cases like establishing new relationships (what, if anything, do you put on business cards?) or allowing the general public or a broad audience to contact you (what, if anything, do you put in advertisements, on your web site, on slides of a conference presentation, in an e-mail signature on mailing lists?).

>Email should have always been a bidirectional address, representing the relationship between the sender and receiver, and not a wide open receiver for anybody who happens to have your address.

Ideally, this would also be the case for physical mail. Multiple revokable tokens, not publicly tied to your physical address.

Dang, you could trade stocks with information like that.