I have used an IMAP account on my Treo 700w that somehow got corrupted, and I had to delete it. Problem is...if I re-create the account under a different name, it keeps having trouble sending mails (complains about "no network coverage"...baloney!!!). I suspect it has something to do with the fact that there are some "leftovers" of the old IMAP account. I can see a key for the name of the old account in:
HKCU\Software\Microsoft\Inbox\SyncServiceProviders

If I delete that account key, as soon as I start the messaging application it gets recreated from somewhere. What the hey? I searched the registry for the account name, but did not get any other hits. What in the world could cause this account registry key to get recreated every time??