
I have recently migrated my lists from an old mailman2 server to a new mailman3 server. The new server is named listservnew and the old server is called lists. Everything is working on the new server using the new name, but after changing the DNS of lists to point to the new server, I am getting Relay Access Denied. We are running this through an F5 and the RCPT from unknown is the F5 IP address. When I add that IP to the main.cf under mynetworks, I get a different error.
Error before changing main.cf: 2025-07-20T22:14:30.381945-05:00 lstprdls01 postfix/smtpd[3713490]: NOQUEUE: reject: RCPT from unknown[10.18.3.105]: 454 4.7.1 <joetest@lists.luc.edu>: Relay access denied; from=<jkoral@luc.edu> to=<joetest@lists.luc.edu> proto=ESMTP helo=<DM1PR04CU001.outbound.protection.outlook.com>
Error after adding F5 IP to mynetworks: 2025-07-22T11:27:13.885111-05:00 lstprdls01 postfix/smtp[174935]: AB1C11C0229: to=<joetest@lists.luc.edu>, relay=lists.luc.edu[147.126.1.184]:25, delay=0.16, delays=0.11/0.01/0.04/0, dsn=5.4.6, status=bounced (mail for lists.luc.edu loops back to myself)
Any help would be greatly appreciated.