> The problem is the cost of creating fake identities. As long as creating fake identities has a fixed cost (increasing linearly with the number of identities you create), there's no way to charge the "same person" exponentially more for sending more email. They'll just create new identities to send new emails.

That's partially handled by my other proposals: People need to pre-approve the senders (otherwise email gets held in a quarantine folder), and people can tack on a fee. Let's make the tack-on fee default to 5 cents.

> If you want a centralized authority for sending messages without spam, then you should just use a popular centralized messaging app. Each messaging app is controlled by a centralized authority, for better and for worse; the general consensus is that spam is a much smaller problem on centralized messaging apps than on email. But centralizing authority is a very high price to fight spam.

The lack of openness is the problem. I'd be happy with WhatsApp if it allowed me to set default policies such as "From person X, don't send me any forwarded messages" and so much more I can't do with WhatsApp that I could do with email.

Ultimately, the solution has to be built into the protocol, and it has to be designed to minimize bad actors not honoring the protocol. May involve cryptography, blockchain, etc (which is why it likely never will be implemented).

> If Gmail thinks your domain reputation is too low, you're gonna have to buy a new domain name if you want to email anybody on Gmail.

Right idea, but wrong implementation. Google shouldn't decide it. You as the individual should have control over the filtering.

> Without one official centralized authority, I think that's about as good as it's ever gonna get.

Very likely true. I can still fantasize.