I have a user on my Ubuntu 18.04 MiaB on IPv4/IPv6 behind pfSense firewall which is behind Comcast router/modem. I have a filter in the user’s account to forward to my old email server (my list server is too old to log into MiaB and get email so I need to continue using my old email server for mailing lists).
Here is the error message in mail.log
Dec 22 22:11:33 mail postfix/smtp: 610ABF60698: firstname.lastname@example.org, relay=none, delay=0.13, delays=0.06/0.03/0.04/0, dsn=5.4.4, status=bounced (Host or domain name not found. Name service error for name=list.server.pminj.org type=AAAA: Host not found)
Why is it not dropping to IPv4 to redirect the email?