Comment 1 for bug 1906970

Hi Klaus,

From your log:
newaliases: warning: valid_hostname: misplaced delimiter: cc1a572af0dc..

That comes down to the initial install&configuration requiring a fully qualified domain name.
And your systems seems to have an invalid one for that use case.

There are two paths out of this.
a) fix the hostname to be a correct fully qualified domain name. Then the postinst config will use that and work.
b) when installing postfix you can select interactively to have it set up with "no config" that allows to manually configure it the way you want it and will not trigger the auto-config code that currently is breaking for you

Which way you choose depends on your preference and your control of the environment.

Fqdn's are a defined standard, and if your name would be like one it should work.
Never the less we try to catch and handle some common issues.
It might be worth for your to look at your hostname in general (report your full name here please) and the code that the install runs you can find in /var/lib/dpkg/info/postfix.postinst - check the function myfqdn for that.
If therein is an issue that could be improved to support your kind of hostname better that might be worth a talk.