Exchange Web Services (EWS) is available for Exchange 2016 (also for Exchange Online). During the writing of the book, we've used EWS Managed API version 2.2, since that was the latest available release. The API gives developers the ability to write applications that previously used legacy APIs.
Today, developers can call Exchange Management Shell cmdlets from .NET-managed applications to perform administrative tasks programmatically. When it comes to manipulating the contents of a mailbox, such as creating or modifying calendar items, email messages, contacts, or tasks, developers now use EWS.
Working with EWS requires formatting and sending an XML request over HTTP and parsing the XML response from an Exchange server. Initially, developers used either raw XML or auto-generated proxy classes in Visual Studio to do this, and it required some very verbose code...
