Good morning everyone, I am installing zimbra here in the company and to transfer the old server running postfix + openwebmail + mailbox without imap to zimbra, I would like a solution, the old server can not stop the migration must be transparent to the End User. I tried to imapsync seeing some tutorials, but I did not have to install an imap client on the old server, this can influence the service on the old server? I would like to do this in the most automated as possible, because they are more than 1500 accounts. I look back. Thank you.