Problem solved for those who cannot sign into their Outlook on a Mac

Over the past few months I have seen numerous requests for assistance regarding the Outlook  on a Mac. The requests always seem to boil down to the same issue; I cannot sign into Outlook. The user will enter their Office 365 password, but it will not be accepted. Confirmation of the password is confirmed with OWA and the Office 365 portal, but regardless it will not work in Outlook.

Original troubleshooting steps involved confirming there were no issues with OWA, which would show account issues on the Microsoft backend. Deletion and creation of a new Outlook profile, or uninstallation and reinstallation of Office. None of these steps however would resolve the issue.

Finally, we discovered the culprit after researching and testing around within the Mac. The issue lies within the credential manager known as KeyChain. The KeyChain will save every Microsoft password, and when your password changes, it does not overwrite it, but instead creates a new entry. After some time, you will notice that you may have dozens of Microsoft entries in your KeyChain and Outlook becomes confused as to which is legitimate. The simplest fix in this case is to delete all credentials pertaining to Microsoft, and start anew.

To do this on Outlook on Mac, please follow these instructions

  • Open Applications/Keychain Access
  • On the left, select the Login Keychain
  • On the left, select the Passwords category
  • Delete the entries with the following names:
    • Exchange
    • Microsoft Office Identities (any)
    • MSOpenTech (any)
    • MSProtection (any)
    • ADAL (any)
  • Close Outlook and reopen

Upon opening Outlook, it will now request your credentials. Enter your current valid credentials and a new key will be created in your KeyChain.

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