On August 7, 2017, at 2:56pm, Michael Slusarz wrote:

This is the RFC 5256 compliant behavior.? From is sorted on addr-mailbox.?

Interesting.

I can't be the only person who's found this to be a limitation, right? It would be very useful to sort by actual sender, not just to group all the michael@'s together, then all the paul@'s, etc.

I'm just a user looking for a workaround, not a protocol architect, but it looks like the RFC also specifies that SORT is extensible, so maybe the most correct, if not the easiest, solution would be to define a new sort key such as DOMAIN.