Microsoft Exchange Server 2007 delivers the advanced protection your company demands, the anywhere access your people want, and the operational efficiency you need.  There is a reason Exchange Server 2007 is the industry's leading server for e-mail, calendaring, and unified messaging. 

The Exchange Server Standard CAL provides access to e-mail, shared calendaring and Outlook Web Access. In addition you will get advancements that reduce the cost and complexity of the messaging system by giving IT Administrators the messaging protection their company demands, the anywhere access their end users want and the reliability they need. This product comes pre-bundled with 20 CALs. You can order additional CALs, if needed.