Server is CentOS 7.1.
After reboot the hostname is overwritten by the transient hostname ("mail") and I can't find a way to avoid that.
Maybe AutoDNS and the MX record "mail" causes that?
/etc/hostname contains the correct value
"hostnamectl --transient set-hostname my.desired.name" is working but only until next reboot
So, after Reboot:
"hostnamectl status" shows the correct static hostname but the wrong transient hostname ("mail").
"hostname -s" or "hostname -f" shows the wrong hostname.

The file /etc/sysconfig/network is overwritten "by anaconda" and has the line HOSTNAME="mail". I tried to set there the correct name but it's overwritten after reboot.

Please give me a hint to change the hostname reboot save. Thanks.