Just a little information on the side, the Exchange Server documentation has moved from Technet to Microsoft Docs. The documentation can now be found under the following link:
The old URLs are still available, so there is no immediate need to update your favorites. The documentation and information on Exchange 2010 and Exchange 2013 can still be found in the Technet.
I find the new site clearer and better structured. Here is the "old Technet" page for comparison:
Microsoft Docs looks somehow more modern, and the new link is easier to remember 
