Login to Your Zimbra Server with root login and password .
Type following commands :-
[[email protected]]# su – zimbra
This Command will change the Console name to
[[email protected] ~]$
Then Type Following command.
[[email protected] ~]$ zmprov -l renamedomain olddomain.com newdomain.com
This has been tested against Zimbra 6, 7 and 8.
Reference: https://communities.vmware.com/thread/459923
thank bro it worked