Promodag Reports can analyze three types of Exchange organizations: On-premises, Office 365, and Hybrid.
Administrators run the messaging system on their own servers, in their own company.
The messaging system is hosted by Microsoft. Microsoft Exchange Online is an email, calendar and contacts solution delivered as a Cloud service and it is part of the Office 365 suite.
Hybrid deployment is a mixed environment: part of the messaging system is hosted in an Office 365 tenant, but the company has kept some Exchange servers on-premise.