Enterprises concerned with Microsoft Exchange Server 2007 availability face better options now that SP1 is out. However, the clustering and replication solutions inherent with Microsoft's software often fall short. Third-party solutions can provide increasingly higher degrees of availability, but should be justified in terms of the maximum time-span of e-mail outage the enterprise can tolerate.

When is Exchange Availability Necessary?

All too often, IT and the business do not communicate clearly about e-mail availability expectations. Over-provisioning availability may make sense from an IT perspective (though at a cost in complexity), but management will want to evaluate the expense. Conversely, under-provisioning ability will lead to a backlash during which IT will be ill-prepared to explain how it arrived at its working targets.