Note Workgroup Mail is an unsupported feature of Microsoft Office Project 2003 and is not planned for future versions of Project.
The Project Workgroup Message Handler is a collaboration tool used by earlier versions of Project that works with the Workgroup Mail functionality. It provides a project manager the ability to communicate with the resources assigned to tasks by using e-mail. Workgroup Mail functionality has been removed as a collaboration option from Microsoft Office Project Standard 2003 and Microsoft Office Project Professional 2003 and is no longer a supported collaboration method. The recommended method for collaboration is to use Microsoft Office Project Server 2003 and Microsoft Office Project Web Access 2003.
If you have used Workgroup Mail in earlier versions of Project and were planning on using it in Project 2003, it can be re-enabled as an interim solution while you plan your move to an alternate method of collaboration for future versions of Project. It is important to note that Microsoft plans to discontinue Workgroup Mail in all future versions of Project, and prior versions of Workgroup Mail will not be supported. In addition, no technical support will be available for Workgroup Mail if any issues are encountered after re-enabling it for use with Project.
If you still want to proceed with Workgroup Mail, you can Download Workgroup Message Handler from TechNet and get instructions for re-enabling it from the following Microsoft Knowledge Base article: Configuring Workgroup Message Handler for Microsoft Office Project 2003.
Workgroup Message Handler is compatible with MAPI-compliant client e-mail applications, including: