I had a weird issue this morning. When logging into all my apps to begin my work day I noticed that my Exchange account wasn’t connecting in Outlook.  We use Office 365 with SSO, and it was continually prompting me with our SSO page to logon in a loop.  I checked the Mail app and everything appeared fine in there, so I knew it wasn’t Office 365 but something with my local Outlook app.  I attempted to remove and readd the account and then started to get “Authentication failed. Check your account information and try again.” It was this point I went to keychain access.  I figured something in keychain had been saved or set wrong and it was passing bad credentials to Office 365 from keychain.  There are 3 sets of items you will need to delete to clear everything being used by Outlook.

  • Open up Keychain Access
  • With “login” highlighted search for the following 3 items
    • Search “Exchange” and delete everything
    • Search “Office” and delete everything
    • Search “ADAL” and delete everything

After I performed those steps, I returned to Outlook and it allowed me to add my account back to the app as expected. I hope this can help others that might have this issue as well.