I recently had a requirement to create a dashboard for Exchange in our organisation. When I tried connecting exchange online through PowerBI, I am being connected to my own mailbox. The requirement is to get reports for whole organisation. I got to know that Exchange server doesn't have SQL database or any APIs to get data from.
Requirement could be getting server availability/performance, usage of mailbox, etc.
The Exchange connector in Power BI only show you a list of items(Mail, Calendar, People, Tasks and Meeting Requests) available in the Exchange account you have entered. It is not possible to use the Exchange connector to analyze the server availability/performance, usage of mailbox, etc.