Chapter 4: Outlook-The Client

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Overview

Messaging servers cannot do very much unless clients connect to allow users to create and send messages. The range of clients available to Exchange continues to expand from the basic Exchange viewer released with Exchange 4.0 to everything from smart cell phones through PDAs to the Web browser, the most widespread client in terms of platform coverage.

Clients do much more than simply create and send messages. Most clients track tasks, appointments, and meetings as well. Some clients are customizable, ranging from the reasonably complete development possibilities in Outlook through simple disabling of feature sets as implemented in OWA.

From a design and deployment perspective, you have to understand the potential of each client from features through supported platforms as well as the implementation and support costs. Some worry about the protocols and application programming interfaces used to build clients, since they would like to select clients that are not going to be outdated and become unsupportable. While it is good to consider this point, in reality it is not an issue for two reasons. First, the decision to deploy client software is often highly influenced by the selection of desktop hardware and software. For instance, if you elect to upgrade desktops to Windows XP Professional, you will probably upgrade hardware as well and may find that the new PCs come with software already loaded or that a bundling deal includes new versions of office application suites. Users end up with the latest version of a browser, Internet mail client such as Outlook Express, or Outlook. It is hard to stop people from using software that they find on their desktop.

The second reason why protocol dependency is not an issue to get too hot about is the fact that Microsoft has a good record of accomplishment in backward compatibility. Every Exchange client shipped since 1996 can connect to the latest version of the server. Almost every browser can connect to Exchange and be an OWA client; and even the earliest POP3 client can still connect to Exchange. None of these clients may be able to use the complete range of features supported by the server, but they will certainly be able to take care of the basics.

Integrating new client types is the biggest challenge facing Exchange administrators today. It is hard to work out how best to incorporate cell phones, PDAs, Pocket PCs, and purpose-built messaging devices such as RIM's BlackBerry into the messaging infrastructure. Every client type connects in different ways; each may require specific hardware or software pieces to relay messages on the desktop or server, and each increases support complexity-not to mention the potential issue of breaking client connectivity when a service pack or hot fix is applied. User desire to possess the latest communications device compounds the difficulty, since it often results in senior management (who tend to be early adopters of new technology even if they do not realize it) demanding support for the latest gizmo. The situation should get easier as devices merge (otherwise, we will all end up resembling a Star Wars storm-trooper equipped with a belt full of different devices) and the myriad wireless protocols used around the world are consolidated, but don't expect this to happen overnight. Client gizmos will remain a challenge for Exchange administrators for quite some time yet.

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