On Wed, 30 Sep 2026 16:32:00 +0100 Chris Green <[email protected]> wrote:
> I also want things like postfix to be able to find the domain. I > discovered this issue when I found that postfix was using > 'localdomain':- > > chris$ postmap -s /etc/aliases.db > postmap: fatal: open database /etc/aliases.db.db: No such file or > directory chris$ postmap -s /etc/aliases > @ @ > YP_LAST_MODIFIED 1786971981 > YP_MASTER_NAME q957.localdomain > postmaster root > root chris > chris$ > The network MTA (and other local workstation MTAs) are the primary users of domain names, and I feel safer configuring them explicitly rather than relying on other software which may or may not be working correctly e.g. resolv.conf. For a network MTA, you need to be quite sure the HELO/EHLO is a hostname with an A record in public DNS, and not just something the MTA or Debian has guessed. It should be OK to use /etc/mailname, as I don't think anything else will change this once configured. -- Joe
