Microsoft Office Outlook 2003 provides a straightforward upgrade path from Microsoft Exchange Client. By upgrading to Outlook, you can help to provide improved features and better integration with other Microsoft Office applications for your users.
Because both Outlook 2003 and Microsoft Exchange Client are MAPI-compatible applications, Outlook can completely replace Exchange Client. Outlook 2003 uses the same profile and other configuration information, and Outlook 2003 should be able to use all Exchange Client extensions and custom forms. Because of this compatibility, Outlook users should be able to exchange e-mail messages and share public folders with Exchange Client users. Some known exceptions are described below.