Hosted Exchange can be used when describing when a service company hosts at their site the dedicated Microsoft Exchange infrastructure for another company. However Hosted Exchange more typically describes a shared hosted Exchange environment that supports multi-tenant hosting. This is where a service company hosts multiple companies on a single Exchange environment. Microsoft Exchange Server 2000 was the first version that could be feasibly deployed in a shared hosted Exchange model.
Configuring shared hosted Exchange was and is a complex process. The use of a provisioning solution such as abrideanProvisorSP provides the accuracy and efficiency required for a commercially successful hosted Exchange offering.
Companies offering shared hosted Exchange include MailStreet.com (A Division of Apptix) and USA.NET. Many of these companies offer additional services such as SharePoint and Blackberry/RIM support. Users of shared hosted Exchange range from single users and "Mom and Pop" businesses to large corporations such as United Airlines.