>This creates a dual-stack operational environment. They always have >real -- and often problematic -- operational effects. Well, we've survived with POP and IMAP for two decades. We might want to put something in the charter noting that the underlying mail has to be RFC822/5322, but the drafts all seem to assume that. Re separating mail pickup from submission, I understand why we decided to keep it separate when we did RFC4409, but that was a decade ago and the mail world has changed. In particular, I don't think anyone in 2006 expected that the majority of mail users would be sending and receiving mail using apps on the phones in their pockets. At this point, if someone says that their POP/IMAP/JMAP and SUBMIT servers need different credentials, I'd suggest that is a cruel joke to play on your users, you should fix it, and while you're at it, you should accept submission through JMAP, too. If you can't fix it, there will still be some IMAP and SUBMIT clients for a long time. R's, John