The following FAQ provides answers to common questions about licensing Exchange. The Exchange Server Standard CAL provides the rights to access e-mail, 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? One server license is required for each running instance of Exchange Server —whether it is installed natively on a physical machine or a virtual machine. Learn more about virtualization support. External users do not require CALs to access Exchange Server ; access rights to standard Exchange functionality by external users is included with the Exchange Server license itself. If several users share a desktop and do not individually access the Exchange server from other locations, such as their home PCs, then they can be licensed with one device CAL.
Sign in Client Access Licenses and Management Licenses If the workstations in your organization are networked, you likely depend on network server software to perform certain functions, such as file and print sharing. A CAL is not a software product; rather, it is a license that gives a user the right to access the services of the server. Likewise, if you manage the devices on your network by using management software such as Microsoft System Center, a Management License ML may be required for the device being managed.
In addition, an External Connector EC license is offered for some products as an optional alternative to address specific customer scenarios. This overview is for reference purposes only. Before purchasing, you should visit the "How to Buy" section for each product and consult your Microsoft representative or local reseller regarding your specific licensing needs.
Purchasing a User CAL might make more sense if your company's employees need to have roaming access to the corporate network by using multiple devices, or from unknown devices, or if you simply have more devices than users in your organization.
Device CALs may make more economic and administrative sense if your company has workers who share devices, for example, on different work shifts. Client Access License based on device RW9TWE External Connectors If you want external users—such as business partners, external contractors, or customers—to be able to access your network, you have two licensing options: Acquire CALs for each of your external users.
Acquire External Connector EC licenses for each server that will be accessed by your external users. An EC license assigned to a server permits access by any number of external users, as long as that access is for the benefit of the licensee and not the external user.
Each physical server that external users access requires only one EC license regardless of the number of software instances running. An "instance" is an installed copy of software. The right to run instances of the server software is licensed separately; the EC, like the CAL, simply permits access. Server Licensing not requiring CALs Some server products are available to be licensed on a "per core" or "per instance" basis.
Per Core licensing Under the Per Core model, when the server software is running in the physical OSE, you must license all physical cores on the server. To determine the number of core licenses you need, count the total number of physical cores for each processor on the server, and then multiply that number by the appropriate core factor. You do not need to purchase additional CALs. Software licensed by core Software licensed by core Specialty Server licensing Specialty Servers are server-only licenses that generally do not require CALs.
Specialty Servers require a server license for each instance of the server software running on a server. You can run the instance in a physical or virtual operating system environment. By exception, some products provide more specific use rights. Included with the ML are the rights to run the corresponding management server software, so you do not need to acquire separate licenses for the management server software. You can also find up-to-date licensing information for specific products at Product Licensing Search.