IT Professionals:
In continued efforts to protect the IU Network and decrease the amount of spam emails sent, on Thursday, March 16, 2023, Campus Networks will block SMTP/TCP port 25 outbound for the Student role, IU Guest role, and all IoT roles within the IU Public net on the wireless network.
When computers become infected with malware, those compromised machines often send thousands, if not millions, of spam emails through port 25 because of its limited security features. Blocking SMTP/TCP port 25 outbound will not eliminate all spam activity but will help reduce the amount sent through the IU wireless network.
The blocking of outgoing TCP port 25 is already a common practice by many Internet Service Providers (ISP), such as Amazon Web Services (AWS), Microsoft Azure, Xfinity, and Dreamhost. In addition, modern email clients utilize encryption and transmit over port 587 to send secure communications.
If you have questions or concerns about this block, please get in touch with the University Information Security Office (UISO) at security@iu.edu.
–IT Community Partnerships on behalf of University Information Security Office