This document that applies to Exchange Server suggests that the bulk of API / Web Services is SOAP based: https://msdn.microsoft.com/en-us/library/office/dd877012(v=exchg.150).aspx
However i see that Office 365 (which i assume is cloud based) supports a REST API. https://msdn.microsoft.com/en-us/library/office/dn776319(v=exchg.150).aspx
But there it says that this documentation applies to Exchange Online / Office 365 only. So if i have an in-house Exchange Server, will it also support REST? Is there some official docu to this end? (i know that it supports EWS via SOAP, but i would prefer REST, and what i found online was just bits and pieces of stories and experiments)
Many thanks...
The only REST API exposed by Exchange on-prem is for accessing user photos. All of the other REST APIs are meant for Exchange Online only, meaning in the context of an Office 365 tenant.