As I've only sniffed om IMAP some years ago, I 'm not the most knowledgeable person on the subject. But I don't think you can include messages on your IMAP server in your backup. What you could do is to copy all IMAP stuff to local folders and backup those. However that kind of defeats the IMAP idea. Best way would be to run a decent backup schedule on your IMAP server.
__________________________________ I'm just a user of The Bat! I don't work for Ritlabs.