How to evaluate if yale.edu messages sent from a non-Yale email service are properly authenticated in Microsoft 365


When using a non-Yale mailing service to send messages using the @yale.edu domain it is critical to ensure that your service is configured to properly authenticate sending mail as Yale University. If it is not properly configured messages will be sent to recipients Junk or not delivered at all.

How do I check if the messages I am sending are properly authenticated?

  1. Send yourself a test message from your service using whatever @yale.edu address you intend to send messages from normally.
  2. On the message you receive obtain the full message headers.
  3. Paste the full headers into the Microsoft Header Analyzer and select the Analyze Headers button.
  4. In the Other Headers section look at the Authentication-Results value.
    • If you see a result that shows dmarc=pass and either spf=pass or a dkim=pass you are configured properly and need to take no other action.
    • If you see a result that shows dmarc=fail and either spf=pass or a dkim=pass then we may already have records added, you will need to contact the vendor to confirm they are validated. 
    • If you see a result that shows dmarc=fail along with a spf=fail or a dkim=fail then you are not properly configured. You will need to complete the approved sender form after obtaining DKIM records, or SPF from your vendor.