We need to send millions of alerting and logging emails per month, mostly to internal recipients. Can we use Microsoft High Volume Email for those and automatically route the small number of external deliveries through another service?
Can I use High Volume Email for internal alerts and route external recipients elsewhere?
Asked by
b__314+waypoint
Answers
Put an SMTP relay in front of the two delivery paths and route based on the envelope recipient domain. Your accepted internal domains go to High Volume Email, and everything else goes to a service that can deliver externally.
Check how the relay handles messages with both internal and external recipients. It needs to split those into separate delivery transactions. The external service will also need a properly authenticated sender domain. Test mixed-recipient messages and failures on each path before relying on it for alerts.
Reply to this answer
Azure Communication Services is another option for the outbound side. SMTP2GO is also worth evaluating. Compare their pricing and delivery requirements against the expected external volume rather than assuming you need to send all your internal mail through them.
Reply to this answer
At millions of messages a month, I'd also question whether email is the right home for all the logs. A central dashboard with role-based access could make the information available to external users too, while reserving email for alerts that actually need attention.
Reply to this answer
Add your answer
Answers are reviewed before publication.
b__314+waypoint:
Would that mean running an SMTP server ourselves? If so, could we just use it for both internal and external delivery?
4x+gasket_862:
You could use a self-managed relay, but compare the operational work and external deliverability requirements with using a separate sending service. The routing layer and the final delivery service don't have to be the same thing.