Businesses of all sizes, from multinational enterprises to small and midsize businesses, are using the messaging and collaboration features of Microsoft Exchange to run critical business functions that if lost, for even a short amount of time, can result in severe business disruption. No wonder Exchange has become a critical application for so many businesses. When these businesses look at high availability to protect key business applications, Exchange is often the first targeted for protection.

This white paper starts by exploring what availability really means, and how availability correlates to RTO and RPO baselines. The concept of "levels of availability" i...