SINCE VERSION 8.1.1
To authorize Email This Issue to access the Microsoft 365 account you’d like to fetch or send emails, you must click the Authorization button in the SMTP Connections or Incoming Mail Accounts.
Once clicked, you’ll be guided through a couple of steps.
Step 1 - Select the Microsoft 365 Account
Follow the set of steps to authenticate yourself in the Microsoft account. Once completed, you’ll get back to Email This Issue either the authentication was successful or unsuccessful.
Step 2 - Verify that the authorization was successful
In case something went wrong, an error message would appear here explaining the causes like this: