Nobody said anything about doing brainless things. There's a lot of sound and fury from Fastmail about JMAP, but the only client is ... Fastmail's web interfac

Nobody said anything about doing brainless things. There's a lot of sound and fury from Fastmail about JMAP, but the only client is ... Fastmail's web interface. I don't care what JMAP wants to do for me as long as it's not actually available to me. IMAP supports downloading headers too -- that doesn't mean everyone uses IMAP 24/7. The IMAP + local synced maildir use case is extremely common and there's no reason JMAP can't do it better. I merely suggest that starting by making small shims for interoperability would encourage protocol adoption so that when clients arise they'll be in a position to be successful out of the gate.