On August 7, 2017 at 3:09 PM Paul wrote:

As far as I can tell, when I ask Dovecot to sort an IMAP mailbox by the From address, it ignores the part of the address after the '@'. So, for instance, mails from info@abc.org, info@xyz.org, and info@ghi.org are all mingled together in arrival order.

Is there a way to change this? Thanks!

This is the RFC 5256 compliant behavior.  From is sorted on addr-mailbox.  If those are equal:

  If two or more messages exactly match according to the sorting
  criteria, these messages are sorted according to the order in
  which they appear in the mailbox.  In other words, there is an
  implicit sort criterion of "sequence number".

RFC 5256, Section 3.

michael