The settings look good. Maybe if you post any error messages, someone here will have suggestions. Thanks.

Hi, David:

Thank you for the response. From what I gathered online, it seemed to have something to do with Microsoft's side.

Regards,

Is SMTP enabled in the tenant? One of the things Microsoft are doing is disabling the SMTP server in the exchange instance used by the domain and the domain admin has to re enable it.

The alternative is to use the OWL add-on as it uses the exchange web service to do it's magic.