spam/ham external email emty from header

[MACscr]

Ok, so I use external anti spam gateways. I have mailboxes setup on those accounts for spam/ham reporting and I have added those to zimbra so that when a user manually moves an email to the junk mail folder, it sends an email to the spam@blah.com address. Anyway, it seems that those emails are forwarded as attachments, which is good, but the from address is showing as empty basically. I mean it does say 'From: MAILER-DAEMON', but there needs to be an address associated with it. Any ideas on what I need to change?