the good news is that generations younger than us don't email, or they at least think it's dumb. I guess the bad news is closed platforms are going to be capturing them.

I like the idea of having fake emails generated for verification / packages - extending that, make them non-human so people can't accidentally memorize and conveniently use them.
e.g. jxhljh34uxb3as7fxuh@scuttlebot.io
you could go further and have a message scuttle-side that you can send to tell the server to deprecate that door into the network once you have the message you need.

I think smart-phone accessabillity is probably one of the main barriers here (remembering that us nerds on laptops are probably a weird minority)