The following IP addresses relay (route) @uchicago.edu mail and are recommended for allowlisting:

• 128.135.176.46 (New as of Mar 1, 2025)
• 128.135.176.47 (New as of Mar 1, 2025)
• 128.135.176.48 (New as of Mar 1, 2025)
• 128.135.176.49 (New as of Mar 1, 2025)
• 128.135.176.50 (New as of Mar 1, 2025)
• 205.208.106.52 (New as of Dec 1, 2024)
• 205.208.106.53 (New as of Dec 1, 2024)
• 205.208.106.54 (New as of Dec 1, 2024)
• 205.208.106.55 (New as of Dec 1, 2024)
• 205.208.106.56 (New as of Dec 1, 2024)
• 67.231.145.199
• 148.163.143.251
• 40.79.65.134

All mail relaying from these IP addresses should be recognized as belonging to the University of Chicago community and allowlisted/exempted accordingly.

The Sender Policy Framework (SPF) record for uchicago.edu maintains current ranges for relaying mail and provides for several off-campus services to send mail from uchicago.edu.

v=spf1 ip4:128.135.176.0/23 ip4:205.208.106.0/24 ip4:167.89.0.0/17 ip4:198.37.144.0/20 ip4:67.231.145.199 ip4:148.163.143.251 ip4:40.79.65.134 include:_spf.google.com include:spf.protection.outlook.com include:s1.uchicago.edu ?all

v=spf1 ip4:52.1.14.157 ip4:107.20.210.250 ?all