With this license type, a license must be assigned for each instance of the server software that is being run.
There are two server editions:
Standard: designed for the mailbox needs of small to midsize organizations. Also
appropriate for non-mailbox roles in a larger Exchange deployment. This edition supports 1 to 5 mailbox
Enterprise: designed for larger organizations that may require a greater number
of mailbox databases. This edition supports 1 to 100 mailbox databases.
Client access licenses (CALs)
With this license type, a CAL is required for each user or device that accesses the server software. There are
two types of CALs for Exchange, both of which work with either edition of the server:
Standard: designed to help users be more productive from virtually any platform,
browser, or mobile device, with features in Exchange Server 2016 that help your users be productive
no matter where they are—while helping protect your organization's
data. To enable Standard CAL features for a user, the user must be licensed with the Standard CAL.
Enterprise: designed to allow organizations to reduce the cost and complexity of
meeting compliance requirements with new integrated archiving functionality and information protection
capabilities, while also helping you cut costs by replacing legacy voice mail systems with Unified
Messaging. The Enterprise CAL is sold as an add-on to the Standard CAL—to enable Enterprise CAL features,
the user must be licensed with one Standard CAL plus one Enterprise CAL.
The following table provides a detailed feature breakdown for each CAL
Standard plus Enterprise
Email, calendar, contacts, and tasks
Outlook on the Web (Internet Explorer, Firefox, Chrome, Safari, and Edge support)
Apps for Outlook and Outlook on the web
Role-based access control (RBAC) capabilities
Per user/distribution list
Default and custom
Default and custom
Data Loss Prevention
Information protection and control (IPC): transport protection rules, Outlook protection
rules, Information Rights Management (IRM) search
In the United States, call (800) 426-9400. In Canada, call (877) 568-2495.