Exchange Server 2007 introduced a new method of labeling messages that pass through the organization called message classification See my article, Using Exchange and Outlook's New Message-Classification Feature (July 2007, InstantDoc ID 96458). Don’t confuse classifications with the Outlook client-specific categories. They are organization-wide labels which can be exposed to certain users. Classifications can be used by Exchange Server 2007 transport agents to control message flow. Message classifications are created on the Exchange Server and need to be exported to an XML file and distributed to Office Outlook 2007 and OWA clients for the clients to use. This process is not automated.

So how can you distribute changes to message classifications to your users that require them? There are two components to consider. First, for clients that have not previously been configured to use message classification, there is a registry entry that must be made on the Windows client. For clients already configured for message classification, any changes made to the XML file that defines the message classifications for the organization need to be propagated to the clients.

The Policy key does not exist in the registry by default. The following registry entry will create the key and define the local client path to the Message Classification XML definition file.

Windows Registry Editor Version 5.00

\[HKEY_CURRENT_USER\Software\Microsoft\Office\12.0\Common\Policy\]

"AdminClassificationPath"="\.xml"

"EnableClassifications"=dword:00000001

"TrustClassifications"=dword:00000001

In addition, the actual XML file needs to be pushed out to those clients as well to the path identified in the AdminClassificationPath value in the registry key. You need to use the actual file path for this value. For example, you could use c:\email\classification.xml. Of course, the XML file needs to match the name in this registry path also.

The biggest deterrent for companies deploying message classification may well be the annoyance of manually maintaining updates for Outlook clients. However, after a company implements a useful set of classifications, they are probably not going to change very much over time. Message classification configuration can be implemented within the standardized corporate Windows client images used for deploying new workstations. Also, Windows domains have built-in tools for pushing out registry changes and file updates such as Group Policy and Logon Scripting. Additional applications also maintain this functionality, such as System Center Configuration Server (formerly known as System Management Server) and the Office 2007 Customization Tool (Office 2007 setup with the /admin switch).