I am working for a company that is currently using GoogleMail for all its corporate email and we want to move to Zimbra. Everyone wants to see all their content (email, calendar, contacts, files), using the web interface, exactly as it is on Google. Most of the users do not with to use an email client and almost all email is retained for historical purposes.
I am not expecting to get everything but do need to get all email and attachments transferred in a very reliable manner. Contacts and Calendar stuff can be re-created as far as I am concerned. There are approx 40 user accounts with some using almost their entire 7.5GB of allocated space.
I also need to make sure that when the MX records are updated to our server that no messages get lost or sent to the wrong server (Google).
Whatever I do I intend to test with a few small accounts first.
Is this a reasonable expectation?
What are the recommendations and things I should watch out for doing such a migration?
Any help would be greatly appreciated.