Back when we first installed Zimbra (v 4.5), there was some internal requirement that all the Zimbra hosts (ldap, mtas, mailboxes) had to be on the same subnet. Maybe it was related to clustering....which we don't use anymore???
We are now running v. 7.1.3 and wonder if the requirement is still the same. We're going to bringing some new hosts online in VMware and are wondering if they have to be on the same subnet as the original physical hosts.