[mjrpes]

One big differentiator is JMAP allows one network connection to track new emails that may get delivered across different folders. With IMAP you need a connection open for each folder.

[kilburn]

Implementing IMAP NOTIFY [1] would be a simpler path assuming you have IMAP implemented already though.

[1] https://www.rfc-editor.org/rfc/rfc5465.html

[mmooss]

Why is that necessarily a good thing? If there's a problem with one folder - or just a large email - all are delayed?

[woodruffw]

Okay, that's a great feature! But I guess I'm asking what the differentiator is if major email providers don't use it.