SMTP Requirements

Email Sender Requirements before UDM accepts delivery of Mail

The University of Detroit Mercy requires all sending domains to have a DNS MX record prior to accepting mail from the domain as well as a reverse DNS lookup record.  This is a common and accepted practice for verifying the legitmacy of a sending host.  Messages from domains without an MX record or reverse DNS record may be dropped without returning notification of failure to deliver.

An MX record or Mail exchanger record is a type of resource record in the Domain Name System (DNS) specifying how Internet e-mail should be routed using the Simple Mail Transfer Protocol (SMTP). Each MX record contains a preference and a host name, so that the collection of MX records for a given domain name point to the servers that should receive e-mail for that domain, and their priority relative to each other.

If you are routinely not receiving messages you expected to arrive into your inbox, please contact the system administrator from the sending domain to verify they have a legitimate DNS MX record for their mail system as well as a reverse DNS lookup record.