[root@kvm7 ~]# systemctl is-enabled postfix.service enabled
[root@kvm7 ~]# systemctl disable postfix.service rm '/etc/systemd/system/multi-user.target.wants/postfix.service'
[root@kvm7 ~]# systemctl is-enabled postfix.service disabled
[root@kvm7 ~]# systemctl enable postfix.service ln -s '/usr/lib/systemd/system/postfix.service' '/etc/systemd/system/multi-user.target.wants/postfix.service'
[root@kvm7 ~]# systemctl is-enabled postfix.service enabled