setting the hostname on ubuntu 18.04 / iRedMail

Hi there

I am a bit confused on how to est the hostname on an 18.04 server.

I intend to use the server as a mail server running iRedMail.

The instruction to set up iRedMail instructs to set :

On Debian/Ubuntu Linux, hostname is set in two

* |/etc/hostname|: short hostname, not FQDN.


and to to set etc hosts:

* |/etc/hosts|: static table lookup for hostnames.*Warning*: Please
list the FQDN hostname as first item.

|# Part of file: /etc/hosts mx localhost
localhost.localdomain |

so what I did:

in /etc/cloud/cloud.cfg

I changed:

# This will cause the set+update hostname module to not operate (if true)
preserve_hostname: true

in /etc/hostname:


in /etc/hosts: localhost

# The following lines are desirable for IPv6 capable hosts
::1 ip6-localhost ip6-loopback
fe00::0 ip6-localnet
ff00::0 ip6-mcastprefix
ff02::1 ip6-allnodes
ff02::2 ip6-allrouters
ff02::3 ip6-allhosts

However when I execute:

hostname -f

I get:


How should I setup the hostname, that I can use the server as a
mailserver for

thannks, robert