On Fri, May 24, 2024 at 11:40:30AM -0400, Greg Wooledge wrote: > 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.
I should note that this is apparently not true for OpenSMTPD. In fact, there is or was a bug in it, such that if you had two instances of 127.0.0.1 in your hosts file, OpenSMTPD would fail with a message that it couldn't listen on address 127.0.0.1 because it was already in use (or somesuch). Paul -- Paul M. Foster Personal Blog: http://noferblatz.com Company Site: http://quillandmouse.com Software Projects: https://gitlab.com/paulmfoster
