There are three main challenges that any organization will typically face: Each individual CAL is tied to a specific version of the server service. However, downgrade rights are always provided: Not all server accesses require a CAL—for instance, with Exchange Server , CALs are not required unless the server access is directly or indirectly authenticated by using Active Directory. CAL Suites offer the benefits of significant discount compared to individual purchases and ease of management—a single license is managed compared to a group of licenses. Additional product use rights are also provided. Once a user or device based CAL Suite is purchased, it is considered as a unique license than cannot be spread across multiple users or devices. CAL Suites are not tied to a specific server product release as they contain multiple CALs tied to products that have their own lifecycle; across all CALs within a CAL suite the related server products may or may not carry the same release number.
Main article: History of Microsoft Exchange Server Microsoft had sold a number of simpler email products before, but the first release of Exchange Exchange Server 4. As of , there have been nine releases. Current version[ edit ] The current version, Exchange Server ,  was released in October One of the key features of the new release is that Exchange Server can be deployed onto Windows Server Core for the first time, additionally Microsoft has retired the Unified Messaging feature of Exchange, meaning that Skype for Business on-premises customers will have to use alternative solutions for voicemail, such as Azure cloud voicemail.
The following FAQ provides answers to common questions about licensing Exchange. The Exchange Server Standard CAL provides the rights to access microsoft exchange server 2013 pricing, calendar, contacts, and tasks through either Outlook on the web, or through a mobile device via Exchange ActiveSync. What are the licensing implications if I choose to run Exchange Server on a virtual machine rather than directly on a physical server?