Chapter Summary

OWA of Exchange 2000 Server is based on the ISAPI of IIS 5.0. It requires Windows 2000 Server and will be installed as an integral part of Microsoft Exchange Messaging and Collaboration Services. Through OWA, users can gain access to Exchange 2000 Server with any browser that supports JavaScript and frames. Ideally, Internet Explorer 5.0 is used.

Based on URLs, IIS determines that Web browser requests must be passed to the ISAPI component of Exchange 2000 Server, and correspondingly OWA will access mailbox and public stores through the Microsoft Web Storage System on behalf of the user. If the Information Store permits access to the resources, the data is retrieved via ExIFS and ExOLEDB, rendered into HTML, interlaced with script elements, and then returned to the browser.

OWA URLs are based on host or domain names. The URLs are independent of individual mailbox or public store locations. In an FE/BE environment, users do not need to know where their mailboxes reside to connect to them. OWA will look up mailboxes in Active Directory to obtain the required information. It is possible to add query strings to OWA URLs to specify a desired action, such as opening a folder or message directly or activating a particular folder view.