We have been speaking with engineers at most of the large mailbox providers and server developers for many years, and made changes to the JMAP spec based on the

We have been speaking with engineers at most of the large mailbox providers and server developers for many years, and made changes to the JMAP spec based on their feedback to make sure it can work for them. You will also find feedback and contributions on the IETF mailing list from some of them. We can’t speak for another company’s product plans however.