I believe ops point was that any stable api would be preferable to: "Yeah, there's an api, but we refuse to document it, and we'll randomly depricate stuff if you try to use it to build something that isn't gmail". The team behind gmail is probably one of the best qualified to hammer out a working api for email of json (what we have + a bit of what we want + stability and versioning). No reason why they couldn't publish that as an RFC and let people implement a front end for dbmail or whatnot that spoke the same api.