Selecting an Edition

Microsoft Exchange Server 2003 comes in two editions: a Standard Edition and an Enterprise Edition. The edition you should select depends on the size of your organization and the Exchange features required. To start, both editions share the same servers, components, administrative and management tools, and so on, with the main difference between the two editions being the number of users they support.

Exchange Server 2003 Standard Edition

The Standard Edition contains the same functionality available in the Enterprise Edition, but it has been designed for smaller organizations that don't need the same enterprise-strength features and functionality as a larger organization.

To start, the Standard Edition supports only one storage group and two databases per storage group. This can pose potential problems when looking at backup and recovery options. In addition, the individual database size is limited to 16GB, which restricts the number of users that the Standard Edition can support, even with Mailbox size restrictions in place.

If you are currently working with Exchange 2000 or another messaging system, you might need to do some investigation to see your current usage patterns before committing to the Standard Edition because you will only have 32GB of storage.

Another key consideration is that you cannot cluster the Standard Edition of Exchange 2003. Some smaller organizations might consider Exchange as a mission-critical application and need the fault tolerance that clustering provides. To cluster Exchange servers, users must buy the Enterprise Edition.

Exchange Server 2003 Enterprise Edition

The Enterprise Edition, on the other hand, is designed to be scalable even for worldwide organizations and can have up to four storage groups with five databases each and up to a whopping 16TB (terabytes) of storage, limited only by the hardware you are using.

This edition also includes clustering capability, allowing administrators to build a robust, fault-tolerant topology that can provide maximum up-time.

In addition, this edition includes an X.400 connector, which can be configured to handle email traffic in and outside your organization. The main benefit of using an X.400 connector is that you can integrate Exchange into a third-party messaging server, which might be required for migration or coexistence.

If you are considering deploying Exchange for a smaller organization, you might want to weigh the cost benefits of the Standard Edition versus the features in the Enterprise Edition. It might seem like the recommendation is heavily skewed toward the Enterprise Edition, but it is better to implement the right version from the start if you anticipate needing any of the features in the future that the Enterprise Edition offers.

ENTERPRISE DOESN'T NEED ENTERPRISE

You can run Exchange's Enterprise Edition on any edition of Windows Server 2003 or Windows 2000 Server; you only have to use the Enterprise (or Advanced) Edition of Windows if you want to use clustering.