The scenario is I need to migrate mailboxes from a qmail server to exchange server. I can use imapsync for that. But the issue is after the DNS change (i.e when DNS changed from old qmail server to new exchange server), there could be some mails in source server too.. So I would like to migrate only those new mails which is in old qmail server to new exchange server.
I heard imapsync can be used incrementally but I couldn't get the documents in the web for that.
So how to perform the migration in this scenario and can imapsync be used in this scenario? Or do you suggest any other tool for this?