Emergency Exposure Management uses Microsoft Office 365 meeting invite data to generate at-risk employee lists. Most users use Office365 in the cloud but you also have users who local Exchange servers. Does the application work with both?
It is not possible to use local Exchange servers; the Exposure Management integration only supports calendars that are available in Office365, not from local exchange servers. To get this to work, you would need to either get your local Exchange calendars into the cloud or move those users to Office365.