Outlook – Caught in infinite loop trying to set up Outlook 2010

Turns out it was an Exchange-side problem. Support told me that for some reason, MAPI was disabled on my account.

I had the same experience. There were a couple of clues as to the cause however:

1. Some people with rights on the resource still could access it.
2. Around the same time, I noticed an increase in the "Sync Issues" emails.

Sadly, the fix isn't fun. The problem lies within Outlook, and not Exchange. You need to wipe away your mail profile and re-create it.

Instructions [Assuming you only use one mail account - see below if you have more]:

1. Exit Outlook
2. Control Panel > Users > Mail > Email Accounts [See below if you have more than one account]
3. Create a new dummy account. Fill it out with fake data (temp@temp.com or something). Don't test.
4. Delete your Real Outlook account. (Don't close this window, you'll want it again soon)
5. Start > "explorer %APPDATA%\Microsoft\Outlook" (no quotes)
6. Delete all the files here.
7. In the Address bar of your explorer, go to %LOCALAPPDATA%\Microsoft\Outlook and delete these files also.
8. Close your Explorer window and return to the Account Settings (E-mail Accounts) window.
9. Create a New account, E-mail Account - configure as per normal for your Exchange server.
10. Delete your dummy account.
11. Start Outlook. It will re-synchronise all your mail, and you'll now be able to access the shared resource again. You may see the remnants of your dummy account in the folder list. Just right-click on it and remove it from Outlook.

If you have more than one account:

If you have more than one account configured, you'll need to be a little cautious with these instructions. You can skip steps 3 and 10 completely. With steps 6 and 7, you'll want to be careful to leave the files related to your other mail account(s). The main files you need to delete are named after your affected email address. In particular the (probably quite large) user@domain.com.ost file.