I really hope that JMAP starts getting some traction, because I've toyed with writing an email client of my own while it's certainly possible to do so, my hope

I really hope that JMAP starts getting some traction, because I've toyed with writing an email client of my own while it's certainly possible to do so, my hope of writing one that people other than myself might actually want to use is quite low. There's so many little nuances and gotchas with IMAP that make it a real bear to work with, plus you have the whole mess of multipart encoding which you might have to roll your own for since not all languages have a suitable library. By contrast HTTP JSON-based APIs are incredibly well-trodden and practically every language has a high quality JSON (de)serializer, many as part of their standard libraries. JMAP would lower the bar for writing email clients dramatically.