Server hostname on the Plesk server should be changed through Plesk CP on the ‘Server’->‘Server preferences’ page with ‘Full hostname’ field. Fill the new hostname and push OK, Plesk will update it’s database and all needed configuration files such as /etc/hosts, /etc/sysconfig/network, /var/qmail/control/me, etc…

Additionally, the hostname will need to be set by Switchlink support within the infrastructure.