While I applaud any effort to make email more usable and secure, I can't escape the feeling that email is quickly becoming the new snail mail. It seems most people only use it for very "official" communication, or communication with more or less autonomous services, while using other channels for almost everything else.

For me at least, email is moving into the same space as a phone number: something you know you need to reliably have, but you'd throw out in a minute if you could get away with it.