Hi @JaksonMikel
Welcome to our forum!
For better research, please provide more details about this case:
What is your account type (POP/IMAP/Exchange)?
Can you log in to your account through a browser?
What does the pop-up prompt look like? If there are screenshots, please be careful to overwrite your personal privacy information.
There are many reasons for this problem, try the following possible solutions:
- Make sure your email account password is correct and up to date in Outlook.
- Remove Your Credentials from The Credentials Manager. Go to Control Panel on the computer, search for Credential Manager, choose Windows Credentials, select the exchange account and remove any stored credentials referencing the Microsoft 365 or ms.outlook email addresses.
- Run safe mode. Windows+R, then type Outlook.exe /safe, and click OK.
- If above doesn't help, using Online Repair to repair Office from the Control Panel. Please refer to the Repair Office from the Control Panel part of this article.
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