We are having to migrate to Exchange 2016 from Exchange 2010 and I am having trouble figuring out the licensing for CALs. Looking at the existing Exchange 2010 cluster (DAG) each server shows total Exchange licenses required is three. We have a small client base but there are at least 30 users that simultaneously use email either via Outlook or OWA. I am trying to see how many CALs Exchange 2016 comes with on its own. For example I recall that Windows Server generally comes with 5 CALs before having to purchase CAL packs. Is this the same for Exchange 2016 Server?