Outlook 2010 (and Thunderbird - see Update 3) has been working fine for a while, but all of a sudden it has been re-prompting for a username and a password and despite it being correct, continues to re-prompt over and over again until it loses the connection to the IMAP server.
I'm still able to get emails pulled down but it is a huge annoyance having to constantly click , ok, ok, ok, ok, fail, connect etc.
Edit: Now it is unable to even load past the splash screen and constantly bombards me with "Enter your user name and password for the following server".
Edit2: After a reboot it is back to re-prompting while being able to use outlook.
Settings are still this:
IMAP setting Server name: blah.blah.com Port: port# Encryption method: SSL SMTP setting Server name: blah.blah.com Port: diffPort# Encryption method: TLS
Update: After doing what I posted as an answer below, it works better overall but I still get repeated prompts. Even while it is actively completing folder checks, it is continually prompting for login info. So it's working... but it doesn't know it is? And it simply won't remember the password... even though it does... It won't remember that it doesn't need to prompt or something.
Update2: It will be fine for a few days (fully functional no prompts) and then out of the blue start prompt-spamming me.
Update3: Thought I'd ditch outlook and go to Thunderbird but I'm having essentially the same problem on Thunderbird. It downloads every email but then complains about being unable to log in properly and claims to disconnect often. The plus side is that Thunderbird is much less annoying about it.