oAuth connection test failure Office 365 - Support and Troubleshooting

oAuth connection test failure Office 365 Issue IMAP and/or SMPT - Email accounts using Office 365 oAuth authentication are failing connection test.

Cause Each oAuth connection requires two tokens: an active and a refresh. So, a typical Office 365 configuration will have a total of four tokens. Two for IMAP and two for SMTP. In case where there are multiple tokens for each connection it's possible that such a configuration might cause conflicts and/or corrupt the record.

Resolution On the instance under investigation. Navigate to System OAuth>Manage Tokens (By typing toke into the navigator) Select Manage Tokens.

If it's evident that there are are multiple tokens for each connection, then you should delete all the tokens and reauthorize the instance by performing a Token Refresh.

This procedure is covered very well by KB0816072 Go down to step number six, paying close attention to this line: You must use an incognito/private window and a local login (side_door.do if needed) to make sure your personal account is not picked up by Microsoft SSO login.

Once that's completed, go back, and retry the connection tests. Depending on the results you may propose the solution or continue troubleshooting knowing you've ruled out a very likely cause.