[Xylakant]

> If you used your preferred mail client, it wouldn't be encrypted end to end

No? Both S/MIME and GPG provide E2E encryption and work with traditional mail clients. Both provide offline access. They also have their problems, but that's another story.

My point is: This is a neat system. It certainly has it's own set of advantages and disadvantages, but it's a centralized system that does not work very much like mail. So don't call it mail.