I have, on my old mail server from which I'm transitioning, half a dozen *really* big (ca 25k messages each or more) mbox format files full of spam.
I know they're spam because, while the usernames are valid on that box, the *mailbox names* were not; there are only 3 valid addresses on the domain and one of them is 'postmaster'. :-)
So, is there any easy way I can feed those raw mbox files into something that will allow Zimbra to train its underlying spam detection mechanisms on them, secure in the knowledge that there is no ham in the bunch?
(Just so I'm clear, the only practical way I see to do this is from the Linux command line on the Z server itself; anything requiring individual handling of the messages is a non-starter due to volume.)