I have been using Zimbra for some time already on a production server ( 5.0 and 6.0 ) using FOSS edition. For now it serves only a few accounts but i am planning on expanding the service to include more mail accounts and i started think about migrating from a single server setup to a multi-server setup. The server is setup up following the Quick Start guide from here : Documentation for the open source Zimbra Collaboration Suite; email, contacts, and group calendaring . Has anyone attempted adding additional mailbox/ldap/mta servers to such a setup and what steps did you take if you did ? Any info is appreciated.