If you are receiving this error when connecting your Microsoft account, it typically means that you have not enabled SMTP authentication under this inbox. To enable SMTP authentication, please refer to our Microsoft setup guide found here for full instructions on where you need to navigate in order to enable SMTP authentication.
Note: If you created your Outlook inbox with Godaddy, you will not be able to enable SMTP authentication this way. You can find a guide on how to get these specific type of inboxes setup here.