IMPORTANT NOTE:  New orders must also purchase a minimum of 5 CALs

Exchange Server 2010 can help you achieve better business outcomes while controlling the costs of deployment, administration, and compliance. Exchange delivers the widest range of deployment options, integrated information leakage protection, and advanced compliance capabilities, that combine to form the best messaging and collaboration solution available. There is a reason Exchange Server is the industry's leading server for e-mail, calendaring, and unified messaging. 

Exchange Server 2007 Enterprise can scale to 100 databases per server.

Microsoft Software Assurance is a maintenance offer that helps your organization get the most from Microsoft software through a broad range of benefits. From deployment planning and staff training to product support and software upgrades, Software Assurance benefits help you increase worker productivity, accelerate organizational performance, and realize a return on your software investment faster.

Microsoft Open Licensing allows the ability to purchase under the same authorization number for two years. Open Business offers volume pricing with only a five minimum license requirement.