If you've enabled 2 Factor Authentication (2FA) or Multi Factor Authentication for Microsoft Office, you may run across Apps like Apple Mail which don't understand 2FA. Not all is lost, however. You can create a single use "App Password" to get around apps that don't support 2FA natively.


Using Mail.app as an example, the scenario basically looks like this:


  1. You enabled 2FA on your Office 365 account and Mail suddenly says you're putting in the incorrect password even though you're not.
  2. Go to Microsoft's security portal here: https://account.activedirectory.windowsazure.com/AppPasswords.aspx
  3. Create an App Password and copy it
  4. Return to Mail and paste it in when Mail prompts for your password


You can create multiple App Passwords for whatever apps don't natively support 2FA.


For in-depth instructions with screenshots, see Microsoft's instructions here:


https://docs.microsoft.com/en-us/azure/active-directory/user-help/multi-factor-authentication-end-user-app-passwords#create-and-delete-app-passwords-from-the-additional-security-verification-page