The Microsoft Visual Studio event service extensions cannot be used on a computer with CDO version 1.21 installed. These extensions are contained in the Exchange.dsm file, which is installed by the Outlook 98 and Outlook 97 Setup programs.
To create and modify event service scripts on a computer with CDO version 1.21 installed, use the server scripting add-in to Outlook 98, which is installed by the Outlook 98 and Outlook 97 Setup programs.