How do you import existing, local email messages into a newly created Zimbra account? I have been using Thunderbird for a number of years, and must be able to import the historical mailboxes into Zimbra, otherwise it will not be feasible to switch. Everything else I've seen so far is great, but this is an elusive piece right now. I've searched the help and all I can find is the Import/Export tab and that doesn't seem to do it. Anyone got a quick hint for this?