I found this thread as I have teh same problem.
I have put the rules in place as you suggest. They work fine in that email
sent via exchange server now goes to the sent folder in exchange server,
and
email sent via my IMAP account ends up in the IMAP sent folder - which is
great
The only problem is that they remain highlighted as "unread" in both sent
folders. Is there a way to do make them "read" by default?
You shouldn't need to set up a rule to move sent items into the IMAP sent
folder - there's an option to do that automatically in the IMAP account
properties...
