Why does a message have [SUSPICIOUS MESSAGE] in the subject line?

One of the products OIT uses to scan messages will append the subject line of a message with [SUSPICIOUS MESSAGE] if the message contains one or more links that trips a flag in the system as potentially unsafe or uses a domain that is known to host malware/viruses.

The links in these messages will be rewritten to begin with http://secure-web.cisco.com. This allows you to safely test these potentially dangerously pages on a proxy server. This server will scan the page for malicious content. You may have the opportunity to trust this site with the following message.

Popup message that lets you select: I don't trust this site or I trust this site.

Whether you trust this site or don't trust this website, that provides feedback to the system to either ease off the restriction of links to this site or to continue block this site for all users.