I'm going to delete a bunch of old accounts on our zimbra server (open source edition).

I'd like to make a backup of the mails for these accounts, but using the open source edition, there's no out-of-the-box solution.

Having to find a file format (maildir or mbox) and a backup method (I only see imapsync), I'd like to hear if someone has some suggestion about that.

I could setup another dummy imap server and use imapsync, then do a backup on it.

Any suggestion ?

Thanks in advance,