I'm going to evaluate upgrading of Zimbra 4.5.10_GA FOSS edition to 7.0.0_GA FOSS (under Red Hat RHEL 5.5).
I've seen that there is some reference about upgrading from 4.x to 5.x or later:
Rolling Upgrades for ZCS - Zimbra :: Wiki
Can this apply to upgrading directly to 7.0.0?
Many thanks in advance!