Who is this article for?

Users who encounter the SharePoint authentication error.

SharePoint Admin permissions are required for some steps.

This article describes how to reset your SharePoint authentication token when troubleshooting authentication issues.

1. Issue
2. Solution
3. Further reading

1. Issue

When launching Outlook, a SharePoint/Windows authentication prompt(s) need to be completed every time.

This can be caused by incorrect information being stored in a specific database file.

2. Solution

You can stop the program asking for authentication each time by deleting the mmAuthStore database file.

To delete mmAuthStore.db:

1. Close Outlook.
2. Clear cache and cookies in your browser.
3. Navigate to C:\Users\<user_name>\AppData\Local\28Hands\Mail Manager.
4. Right-click the mmAuthStore.db file.
5. Select Delete.

After following these steps, you will need to enter your credentials once, but you should no longer be prompted to sign in the next time you launch Outlook.

If this still doesn't resolve the issue, follow the steps to capturing diagnostic information for troubleshooting. This will help our Support Team investigate it further.

3. Further reading

• Troubleshooting "Error occurred getting authToken: Hostname check for tenancy failed" pop-up