Are you frustrated with Outlook Web Access (OWA) for Exchange Server 5.5? I often hear complaints about the limitations and shortcomings of OWA. Hold on. Hope is on the horizon with Exchange 2000's version of OWA.
The problems that we encounter with Exchange Server 5.5 OWA center around installation and configuration complexities, difficulties in troubleshooting, lack of scalability and performance, and weak feature support. The fact that Microsoft's Support Online is full of articles on problems with OWA is one good testimony. Most OWA problems have to do with the implementation. OWA for Exchange Server 5.5 is not truly a Web-based client; instead, it uses a proxy Messaging API (MAPI) approach. Browser clients accessing Exchange via OWA send a request to Internet Information Server (IIS), which translates the request via Active Server Pages (ASP) scripts to MAPI calls to the user's Exchange server. This approach results in a complex scenario to deploy, manage, and troubleshoot Exchange. The scalability is also severely limited because developers did not design ASP and the IIS scripting engine for this task.
Microsoft is intimately familiar with these shortcomings and has vowed to make things much better in Exchange 2000. Indeed, it has. The advent of the WebStore in Exchange 2000 has solved most OWA issues by making all content directly URL-addressable (no need for MAPI by proxy). Along with this, Exchange 2000's installable file system driver (ExIFS) makes getting at streaming and MIME data very fast and efficient.
Microsoft has done a lot of work to improve things on the browser side also. New protocols such as Extensible Markup Language (XML), Dynamic HTML (DHTML), and HTTP/Distributed Authoring and Versioning (DAV), as well as other improvements in browser technology, have made OWA in Exchange 2000 much more worthwhile to investigate for your deployment.
Another significant advancement is the uncoupling of Internet protocols such as HTTP from the Exchange information store (IS). Now, IIS handles all client requests for Internet protocols and offloads these tasks from the Exchange IS. From a scalability point of view, OWA makes a good candidate for Exchange 2000's Front-End/Back-End (FE/BE) architectural option. On a front-end server, IIS services requests and accesses client data on back-end store servers. A bank of front-end protocol servers can service a huge population of browser-based clients and provide a high degree of scalability and reliability.
While not available yet, OWA for Exchange 2000 promises some huge advantages over its predecessor. The administrative advantages alone are worth a second look if you've written off OWA for Exchange Server 5.5. More importantly, OWA for Exchange 2000 is a true Web-based access paradigm that will provide a much more reliable, high-performance, and feature-rich experience for browser-based clients and applications for Exchange 2000.
