It was suggested on the #freedombox IRC channel that my recent experience with postfix on fbx might be related to this bug. I'll briefly relate experience here, therefore, in case it might be useful. I hope it isn't noise.
I had a working postfix setup on fbx 23.6.2 setup. Because the Debian 11 -> 12 transition had frozen uploads, and because the change in the way apt handles the labels stable and <code name (bookworm in this case)> changed in bookworm and required making a config change to apt, I didn't get an upgrade of my fbx package until 28 July 2023 at 01:38 UTC, which was from 23.6.2 to 23.13~bpo12+1. Shortly after that I discovered that mail destined for users of my fbx was being rejected by postfix with "Diagnostic-Code: smtp; 454 4.7.1 <joe...@mydomain.com <mailto:joe...@mydomain.com>>: Relay access denied" It turns out that postfix's main.cf file had been overwritten on 28 July 2023 at UTC 01:41 with no real configuration in it. At least, there was no mention of mydomain.com in the file anymore, nor to any fqdn, for that matter. On IRC I learned that the postinst script in the postfix package is run at each upgrade. The suggestion was that possibly the postfix postinst script was responsible for overwriting my working main.cf The behaviour I would like to see is as with other Debian packages that are about to overwrite an existing config file: * A dialogue appears explaining the situation where you can choose to let the package overwrite the file, saving the original with a .dpkg-old suffix, to keep the original file, while writing the pkg maintainers version to <file>.dpkg-new, or to examine the differences between the two files before deciding. Fortunately I had a backup of the working main.cf, so recovery was much simpler than figuring out why my setup had quit working. If any interested parties would like more information about my experience, ask, and I will do my best to find that info for you. -- joeDoe
