On 18 April 2017 at 16:35, Christoph Pleger <christ...@plmail.de> wrote:
> Hello, > > I have here two different postfix installations, one is postfix 2.11.3-1 > from Debian 8, the other is postfix 3.1.0-3 from Ubuntu 16.04. /etc/postfix/ > main.cf is the same on both machines, mydomain and myhostname are not set > in main.cf . When I call postconf, I get > > mydomain = cs.uni-dortmund.de > myhostname = cloudhost177.cs.uni-dortmund.de > > on the Debian machine, but > > mydomain = localdomain > myhostname = cloudhost176.localdomain > > on the Ubuntu machine. >From http://www.postfix.org/postconf.5.html#myhostname: the default [for myhostname] is to use the fully-qualified domain name (FQDN) from gethostname(), or to use the non-FQDN result from gethostname() and append ".$mydomain" - i.e. what you see when you type 'hostname' at the command line, which in turn is usually taken from the contents of /etc/hostname. And mydomain is by default derived from myhostname. If you update /etc/hostname you may also need to update /etc/hosts.
