If you’re changing your system and trying to reconfigure your zimbra, you might have to use the following commands:
su – zimbra
The above commands come very handy when you might have mistakenly typed a wrong hostname and configured zimbra to continue using it.
Before making changes to the zimbra server name, ensure the hostname and the DNS is configured fine.
For more info refer to: https://wiki.zimbra.com/index.php?title=Zmsetservername