Microsoft Exchange server downtime costs companies millions of dollars a year. Technically savvy IT organizations are therefore working to eliminate or lessen the impact of both planned and unplanned downtime through the implementation of high-availability systems and disaster-recovery systems. However, building a geographically dispersed Exchange cluster is not a simple task; it requires proper planning, testing, deployment and validation. By understanding the issues raised in this discussion and considering these recommendations during the planning stage, you will have taken the first and most critical step toward deploying the system that best meets your business objectives.