Silent Mail had to inter-operate with other mail services and users (many of whom have no desire to use PGP). That means we had to touch plaintext at times (eve

Silent Mail had to inter-operate with other mail services and users (many of whom have no desire to use PGP). That means we had to touch plaintext at times (even if it was just an incoming message from a non-Silent Mail user, prior to us encrypting it and storing it for our user). It was different from the other products because mail inherently doesn't allow end to end encryption without a lot of manual key management (which is exactly why no one does it). Some day we would love to offer a service that _can_ do that, but email, in it's current form, can't do that for us. Speaking personally, I'm very excited about projects like Adam Langley's Pond.