Some of you may have heard of #simplex which likes to elevate itself as "the first messenger without user-ids" ... a goal, similar to ours, of not letting the transport layer know about who talks. Only we are doing it in the email system, fully interoperable with tens of thousands of existing email servers and other #openpgp endpoints. The email system is much more than SMTP/IMAP or even openpgp btw ... there is plenty of room for radical shifts and new takes. We are just starting :)