I am looking for a solution by which mails which are on my in house zimbra mail server should be synced with backup mail server which we have subscribed. This mail server is simply and Postfix/Dovecot server and has IMAP/POP functionality available. Thus we do not want to invest on another zimbra mail server and can have a redundancy by which if my primary mail server goes down users at least can access their mails using web mail which will are stored on backup mail server. Any ideas? I can think of imapsync to run continuously or may be at certain interval and sync the data..
Any other ideas guys you can think of?