No biggie, just create another domain & move the user's to it - depends on your hostname/hosts file/DNS records at the time you installed.
Don't delete your old domain, there's still lots of references to it.
zmprov gacf | grep linux-1hqz.private.lan
zmlocalconfig | grep linux-1hqz.private.lan
For instance the spam accounts & default login domain, daily reports etc:
zmprov mcf zimbraSpamIsSpamAccount
spam@domain.com
zmprov mcf zimbraSpamIsNotSpamAccount
ham@domain.com
zmprov mcf zimbraDefaultDomain domain.com
zmlocalconfig -e smtp_destination=admin@domain.com