Forum Discussion
Security Considerations for SMTP Add-on Service Receiving Emails from Exchange Online
Hello everyone, I'm developing an email processing service for Microsoft 365 / Exchange Online customers. This service acts as an SMTP endpoint that receives all outbound emails from our customers' ...
First of all, why would you reroute outbound email back to the tenant?
For final delivery. It is what MS suggested in the article (see the link in the original post). It can be Mimecast or smth else. It does not matter, I think. My concerns are related to emails coming from EO to my service.
