Why doesn't Microsoft Outlook 2002 appear as one of the items in Protected Email client in AntiVirus 2001?

Why doesn't Microsoft Outlook 2002 appear as one of the items in Protected Email client in AntiVirus 2001?

Please refer to the following solution in Symantec's website for the procedure to make the changes/settings manually.

Solution: How to configure Microsoft Outlook 2002 to use Norton AntiVirus 2001 email protection?
Url: http://www.Symantec.com