Ok, did a search and couldn't find much on the current mail server topic, the importing I could use the imapsync but if zimbra can be installed on the current mail server then if I could just copy the directories or something like that, would be much easier.
So currently we have a dovecot/postfix setup with roundcube webmail. Was thinking of installing Zimbra on the same server then trying to copy the messages. The two questions are, is it smart to install on the current mail server and can I just copy the messages across? OR should I install on another server, imap sync then, rebuild the mail box (OS could use an update), install Zimbra, backup the temp server then copy over to production server?
Not sure which is the best method for doing this. Breaking the email isn't an option :-/ (Of Course...no one can live without email these days)