IMAP From sort uses only local-part

[Paul]

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 i...@abc.org, i...@xyz.org, and i...@ghi.org are 
all mingled together in arrival order.

Is there a way to change this? Thanks!