ALERT! Firewall change restricting external email delivery


This information was sent to HITS staff via email February 3, 2021.  It is intended for HITS staff who are responsible for applications or servers sending external email which have NOT been configured with a HITS email relay server.


A Firewall change will take place on Thursday, February 4 at 5:30 a.m., restricting external email delivery to authorized internet email servers. This change is in response to malware infecting a personal device that began sending spam. As a result, a major Internet Service Provider (ISP) began blocking all email from Michigan Medicine, impacting clinical operations and patient communication.

Action Required

  • All servers and applications sending external email (address not at must use the HITS email relay.
  • Servers and applications not already using the HITS mail relay server can be configured to use the service hosted by the HITS Windows Hosting Team.
    • To use the HITS email relay:
      • Assign a ServiceNow INC ticket directly to the Windows Hosting Team to have the sending IP addresses added configuration white-list.
            • Test to verify that your application can open a connection to on tcp port 25. 
      • Configure your application to send to

Need help?

Please submit a ServiceNow INC ticket directly to the Windows Hosting Team.

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