@obrhoff @atlauren I mean to be clear the claims of JMAP really are complete nonsense.
IMAP is awkward but hard to beat on efficiency, and the awkward part doesn’t matter that much because the libs are available.
If they would have branded that on what it is, mail for web clients, it would be more reasonable.
I suspect it’s because they can’t do stateful efficiently with Cyrus because it’s old, but I’m not sure.