On Windows 10, I've used the provided email client to add a non-Hotmail Exchange ActiveSync account; this works fine. (The Exchange server only supports off-site access to mobile devices; it is not configured for Outlook Anywhere.)
However, when I follow the corresponding steps in Outlook 2016, I get an error of "Log onto Exchange ActiveSync mail server (EAS): The server cannot be found." (This didn't work in Outlook 2013 either, so at least it isn't a regression.)
My expectation is that I would not lose functionality when switching from the free Microsoft-provided email client to Microsoft Outlook 2016.