On Sunday, November 13, 2022 7:26:25 PM EST David wrote: > Folks > I'm noticing that two installations of Postfix: > version 3.4.13-0ubuntu1.2) on Ubuntu 20.04.5 > version 3.6.4-1ubuntu1 on Ubuntu 22.04.1 > are both failing to use the MX value for outgoing > mail. Specifically, sending mail to any...@sonic.net (forget that no > such account exists) should be connecting to the mail exchange at > mailin-01.mx.sonic.net or mailin-02.mx.sonic.net and NOT to > sonic.net. The contents of the /var/log/maillog show the attempted > connects to sonic.net which obviously fail, since "sonic.net" is not > a mail server. > > In both cases, I'm running BIND9 to serve a local network, and am > using systemd's resolvconf. In both cases, also, both "dig mx > sonic.net" and "host -mx sonic.net" produce the correct MX values. > > I have been unable to figure out what knob or switch or setting might > be causing this behavior; any pointers or clues would be > appreciated. I can supply copies of configuration files if someone > wants to dig further.
Debian puts Postfix in a chroot by default. Ubuntu inherits this from Debian. The view of what's in DNS may not be the same inside the chroot as it is outside. I'd recommend taking them out of the chroot and seeing if that fixes the problem. Scott K
