On Fri, May 24, 2024 at 05:22:14PM +0200, Marco Moock wrote: > Am 24.05.2024 um 17:17:45 Uhr schrieb to...@tuxteam.de: > > > On Fri, May 24, 2024 at 04:49:18PM +0200, Marco Moock wrote: > > > > [...] > > > > > If you operate mail servers, you must have a FQDN. .lan can't be > > > used for the global DNS stuff, so set a proper FQDN that belongs to > > > you. > > > > I think this is wrong in that sweeping generality. > > In the case it should communicate with other MTAs in the internet, this > will be true because many of them require a resolvable (also reverse) > FQDN in HELO/EHLO that matches the IPv4/IPv6 addresses of the server.
Most MTAs do not look in /etc/hosts when reading their configuration. Whatever name they identify with (in the HELO or EHLO command) comes from some MTA-specific configuration file. Thus, the contents of /etc/hosts are for *other* things, not related to MTA configuration. Just being able to resolve your own hostname to any address that "works" is the goal. 127.0.1.1 works well for this, which is why Debian uses it as the default. If you've got a static LAN address, you can use that instead.
