Encrypted email is pretty much over in 2017. The emerging consensus among experts is that it's not worth the trouble, or, worse, incapable of doing much more than generating a false sense of security. That's for a bunch of reasons: * An enormous installed base of clients that won't do encryption, meaning that at best you're attempting to tunnel encrypted messaging over an unencrypted transport. * A protocol that leak…
This is all true, but IM is not email. What I want out of email that IM does not (generally) deliver: 1) UI optimized for longer form messages. 2) Decentralized system where you can send to anyone if you know their address, which may be long-lasting and not tied to the fortunes of a single private company. I don't demand compatibility or interoperability with SMTP, but I also don't want to throw the baby out with the…
At the same time: if you had to compare the UX of running a long-term secret conversation over Signal versus the UX of trying to reliably encrypt messages over email, no normal user would ever choose the latter.
Secure messenger UX will get better long before email will be reliably encrypted (that's cheating, because email will probably never be reliably encrypted, but even if it wasn't, messenger protocols are going to win this race).