The REST-based Exchange service first released with K2 Five (5.1) and K2 Cloud Update 4 connects to a Microsoft Exchange server using its REST API. This service uses OAuth authorization and allows you to integrate with Exchange Online whether you have K2 Five or K2 Cloud.
The REST-based Exchange service is not linked to the Exchange workflow event wizards. You can use the SmartObject methods when designing workflows, however, the Exchange wizards in the designer use the existing Exchange brokers which are not capable of connecting to Exchange Online.
Use the following tables to compare the SmartObject properties of the Exchange Management service with the matching properties of the REST-based Exchange service.
See Exchange SmartObjects Reference for more information about using the REST-based Exchange service.