If a gmail user sends a plain text email to a lavabit user or vice versa, do they consider that scenario to be "fully encrypted". Or do both recipient and sender have to be lavabit users?
they perform(ed) encryption of your inbox using your account password, which they (obviously) don't store. Thus, everything you save to their servers is encrypted by them on your behalf, and they can't decrypt it without you.
if you email a gmail account, or a gmail account emails you, obviously a copy will end up on both, at least temporarily.
I don't see what more they could do, as a provider - all your metadata and emails encrypted properly for you, shut down completely when (the NSA?) comes knocking.
