is there any project (probably should be email server) which would use pubkey hash (secp256k1) as identity?
example: `0x9be5d213245be984c0fb806a1d92c03a05448a4d@example.com`
It would still accept SMTP as backward compact and also implement e2e protocol without leaking metadata on side. It could implement other endless cool stuff on top of that (roaming with notifying addresses that you moved to new @example2.com. Send some crypto for better ranking in inbox as optional spam protection.