Exchange Server 2007 - 5 Add-On User CALs The Exchange Server Standard CAL provides access to e-mail, shared calendaring, contacts, tasks, management, 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. Exchange Server 2007 Standard Edition is designed to meet the messaging and collaboration needs of small and medium corporations.  It may also be appropriate for specific server roles or branch offices.