Out of interest, has anyone moved internal domains with Zimbra?
External is the same (whatever@school.lea.sch.uk) however with an entirely new network structure this summer the internal (currently school.internal) will be moving to fullschoolname.internal) and obviously with different IP addresses.

The theory seems easy, in the admin console under authentication just move the domain and IP's to the new ones. Usernames and passwords will remain the same from old AD to new. So therefore just change them and job's a gooden, but we're concerned that seems too easy. We plan to do a little testing, obviously, but if anyone's done the same I'd be interested to hear experiences.