IT is a minefiled. The big vendors are not on our side. KISS is the golden IT rule.
Whenever you find you have duplicate sent boxes or spam mailbox settings, pick one and make it the blessed folder across all computers.
Trouble with your IMAP after a server move? Here are the setting you need to change in Apple Mail to save messages properly.
Having trouble with draft messages proliferating like rabbits in IMAP in Apple Mail? Here’s the solution.
The whole investment was totally worth the money and these guys are top of the list if such situation comes up again. And if I hear from somebody wanting to do the same, I'll be sure to recommend them.