I agree with most of Dave Crocker's comments and don't have much time to spend on a proposal that, if approved, I believe (for reasons that overlap those he cites) will, like many of its predecessors, die a quiet death after wasting a lot of time. However, the exchange surrounding one of Randy's comments prompts a further remark or two... --On Wednesday, February 8, 2017 05:03 +0900 Randy Bush <randy@xxxxxxx> wrote: >> Why? You will either be using IMAP/SMTP to access your >> mail/submit your messages or you will be using JMAP. If you >> have the option of the latter, youʼve just halved the number >> of things that need configuring. > > how does the server forward the submitted mail to the global > internet? > > how does the server migrate 200 or 2,000 imap users at human > speed, i.e. over months? So, suppose I have a mail server that, because it is configured in the real world, has to support SMTP and IMAP (and maybe POP3) for existing users while trying to support new MUAs that use this JMAP stuff. Randy suggests that requires configuring three kinds of systems. I suggest that he underestimates the problem. First, there is not just "configuring" but "supporting". Working with configurations may be an infrequent activity. Providing support is a continuing one and takes time, even if one's idea of support is saying "what do you want for nothing, figure it out yourself" in a firm tone and at frequent intervals. A change from an IMAP/SMTP base to supporting a new model or representation and systems that provide it vastly increases that job, and increases it by at least a factor of three (old one, new one, people considering or trying to make the transition). Second, there is an issue that Randy and Dave both hinted at in different ways. Unless the proposal is to use Jmap end to end, replacing SMTP, conversion issues have to be worked out. The community made a series of decisions around the time MIME was adopted that essentially require that the SMTP payload be either unstructured messages (essentially conformant to 822) or MIME. The previous (albeit controversial) idea that, other than trace fields inserted by SMTP MTAs, SMTP could treat the message as header-free and opaque and carry material that was not at least 822-conformant is history. That means one needs to configure, maintain, support, and debug: SMTP IMAP JMAP SMTP/Standard Message Headers -> JMAP for inbound messages JMAP -> Message Submission for outbound messages. That is a big deal. There better be a lot of added value to justify it or it will go nowhere (a slightly different negative analogy to the rapid and overwhelming success of IPv6 is perhaps obvious), just as a variety of grand solutions to real or imagined problems with email have gone nowhere. With this proposal, I see some small incremental improvements for systems that are working in JSON environments anyway, but nothing that would justify widespread implementation and deployment. The answer might be different for a mail system that assumed that all users would be using the same mail store and either webmail or JSON-based clients/MUAs. But such mail systems exist only in proprietary walled gardens and should not be IETF topics except possibly for mail gateways to and from them. And those gateway raise most of the issues outlined above. TL;DR summary: Just say 'no'. john