HmC SMTP RELAY
An HmC mail relay is only accessible from HmC systems in the Hanscom Cloud (i.e. not available from HmC systems in AWS or Azure or anywhere outside Hanscom). HmC is not planning to host an external SMTP forwarder.
Please reach out to email@example.com if you have any questions about how to utilize the SMTP Relay.
SMTP Relay Details
mail.hmc.hpc.mil, port 25, no ssl, unauthenticated