Outlook keeps prompting you to login to Microsoft services
Applies to
- Windows 10
- Office 2016 / 2019
Issue
It may happen that you receive a login prompt from Microsoft Online Services when starting Outlook. You may close the window but the message come back aster a few seconds. This prompt also stops the mailbox to be synchronized.
The case
In my case, the emails where hosted on a on-premise Microsoft Exchange server, so they were no reason we should sign it to Microsoft Online Services.
Problem
The user email address was registered to a Microsoft Personal Account. Outlook seems to check your email address with registered accounts and asks you to login should it find it. It sort of forces your to use it.
We’ve tried to delete the account but you have to wait 60 days as Microsoft allows you to restore it. The account is still detected as existing by Outlook during that time.
Solution
You will need to clear all traces of the Microsoft Account.
Outlook
In Outlook go to File then Office Account.
Then, in the User Information part, click on Sign Out (you should see the email address associated with the account)
Windows Settings
- Open the Start Menu and go to Settings
- Click on Accounts
- Go to Email & accounts
- Sign out of the email account you find here
Test
Reopen Outlook. It should be fine now.
(Bonus) OfficeFileCache
Should it still be troubling you, a Microsoft technician recommended to rename the following folder. You will have to make sure all office programs are properly closed as it contains a database that might still be accessed by a process.
C:\Users\<YourUsername>\AppData\Local\Microsoft\Office\16.0\OfficeFileCache