Thanks for the idea. I don't think our destination server removes the tags though.
We're delivering to a groupwise server and have been performing mail filtering for some time through a different homebrew service (using MailScanner). I just checked one of the older messages (below)
When sending a test email (including copied bits of spam messages to push the points up for SA) into a local account on the zimbra server; the mail gets flagged, subject rewrite, and delivered to 'junk'.
Sending the same message for delivery to a relayed domain, we just get the virus scanner header; no spam flagging, no subject rewrites, etc.
Thanks again for your thoughts sumo
Subject: [SPAM] Personal postmaster 79% Off
Content-Type: text/html; charset="ISO-8859-1"
X-DCS-MailScanner-Information: Please contact the ISP for more information
X-DCS-MailScanner: Found to be clean
X-DCS-MailScanner-SpamCheck: spam (blacklisted)