Classifying Messages in Exchange 2007, Part 3

In the previous article in this series, I explained that message classifications are not exposed through Outlook by default. In this article I want to show you how you can expose message classifications to Outlook 2007 users.

Before I Begin

Before I get started, I want to point out that the technique that I am about to show you involves editing the registry. Editing the registry is dangerous, and making a mistake can destroy Windows and / or the applications that are running on the system. I therefore recommend making a full system backup before attempting what I am about to show you.

The .XML File Path

Now that I have made the lawyers happy with my disclaimer, let’s get started. In the previous article, I explained that you have to make Outlook aware of any classifications that you plan on using. You can accomplish this by exporting the message classifications to an .XML file, and then making that .XML file available to Outlook.

One of the first things that you will need to consider though is where you want to put the .XML file. You can place the .XML file anywhere that you want so long as the location meets two conditions. First, the location has to be accessible to the end user and to Outlook. Second, the location has to exist in such a way that you can enter a path to the location in the registry.

Of course this brings up the question of whether you should place the .XML file on a network share or on the local computer. To be perfectly honest, I haven’t quite decided which method is better. Microsoft supports both local and network paths, but recommends using a local path. Even so, there are advantages and disadvantages to each location.

The primary advantage to using a network path is manageability. If you point all of your network clients to a single network path, then you only have to maintain one copy of the .XML file. Any time that you need to add a new message classification, you will only have to update a single copy of the .XML file, rather than having to push the file to every single PC. Of course most organizations do not update their message classification file often enough for this to become a real issue once the organization has been using message classifications for a while, and has had time to figure out which classifications they really need.

The reason why Microsoft recommends keeping a local copy of the .XML file on each individual machine is because if the .XML file is stored on a network share, then the network connection can be a single point of failure. If the network connection were to go down, then users can continue to use Outlook in cached mode to read any E-mail messages that have already been delivered, and to compose new messages that will be sent when the connection becomes available again. However, unless the .XML file is stored locally, then the users won’t be able to classify messages or view existing classifications on messages that have already been delivered.

Editing the Registry

Regardless of which path you have chosen to use, there are three registry entries that you will need to create.  All three reside at HKEY_CURRENT_USER\Software\Microsoft\Office\12.0\Common\Policy.

The first key that you will need to create is AdminClassificationPath. This key should contain the path to your .XML file. I will cover the .XML file in the next part of the article series, but for now, just call the file Classifications.XML.

Next, you will need to create a DWORD key named EnableClassifications, and set its value to 00000001. This is the key that actually makes message classifications available to Outlook 2007.

The third and final key that you will have to create is the TrustClassifications key. Again, this is a DWORD key, and you will need to set its value to 00000001. This key allows you to qualify the assertions made on classified messages that are being sent to recipients whose mailboxes reside on Exchange Servers that are running Exchange 2003 or an earlier version.

Keep in mind that these registry entries should only be made for users whose mailboxes reside on Exchange 2007 servers, and who are running Outlook 2007. You can see what the registry entries look like in Figure A.

Figure A This is what the necessary registry entries look like.

Conclusion

In this article, I have talked about the registry entries that you will need to create in order to make message classifications available to Outlook 2007 users. In the next article, I will conclude the series by showing you how to create the .XML file used by message classifications.

Got a question? Post it on our Exchange Server Forums!