Step by step guide:
1. Install CentOS 6.2 minimal
2. Stop Postfix by running ‘service postfix stop’ and disable it at boot time ‘chkconfig postfix off’
3. Install a few required packages ‘yum install nc perl sysstat libstdc++.i686 wget nano’
4. Use any text editor to comment ‘Defaults requiretty’ out in sudoers. You can find the file in /etc/sudoers or by typing visudo.
5. Download the lastest version at zimbra.com
6. Extract using ‘tar xvf zcs.x.x.x’
7. Install by using ‘./install.sh –platform-override’.
8. Follow the steps in the setup guide.
Don´t forget to edit the firewall rules & edit the /etc/hosts file!!