Client-Side Licensing

Clients with mailboxes on an Exchange Server 2010-based system require both Exchange Server 2010 Client Access Licenses (CALs) and Windows Server 2008 CALs—the latter are required because Exchange Server 2010 runs on Windows Server 2008 (with SP2) or Windows Server 2008 R2, and a client of either version of the OS must be licensed via a Windows Server 2008 CAL. In addition, PCs that use Outlook as an e-mail client require an Outlook license (acquired separately or as part of an Office suite). However, use of Exchange Server’s browser-based interface (called Outlook Web App, or OWA) does not require additional licenses beyond the CALs, and the code and license for Microsoft’s Outlook Mobile client ships with Windows Mobile smart phones.

CALs and External Connectors

As with Exchange Server 2007, accessing the full Exchange 2010 feature set requires customers to purchase two different CALs, a Standard CAL (SCAL) and an Enterprise CAL (ECAL). The SCAL, always required, licenses Exchange’s essential features (such as e-mail, calendar, contacts, tasks, browser-based access, and basic mobile device support). The ECAL, which is optional, licenses the remainder. (For a summary of the SCAL and ECAL features, see the illustration “Features Licensed by Exchange CALs“.)