The server’s hostname conflicts with domain ownership for the user "USER"

Symptoms

You received the following notification with the subject 'The server’s hostname conflicts with domain ownership for the user "USER"' where "USER" is a cPanel username.

The server’s hostname conflicts with domain ownership for the user “USER”.
The server’s hostname “domain.tld” is currently owned by the user “USER”.
A user should not own the hostname because this will compromise the
integrity and security of the system.

You can resolve this conflict by doing one of the following:

Set a new hostname for the server at https://hostname.tld:2087/scripts2/changehostname.
Set a new hostname for the server with the following command: ” .
Remove the domain “domain.tld” from the user “USER”.
Log in to cPanel at https://hostname.tld:2083
Remove the domain from all areas in the “Domains” section.

If you do not change your server’s hostname, your server may experience problems
withmail, internal cPanel scripts, and other important services.

Description 

This occurs when the hostname of the server is set to a domain that exists on a cPanel account.

Workaround

Change the hostname of the server to a fully qualified domain name that will not be used on a cPanel account by following the articles linked below:

Effective Hostname Usage With cPanel & WHM

How to change the server's hostname from WHM