We are trying to develop a outlook addin for new outlook and testing using Outlook 16.75.2 on Mac desktop app. We have "OnMessageSend" / "OnAppointmentSend" working to get javascript callbacks when ...
Please add an Outlook function OnAppointmentCancel for Calendar events so it's possible to rollback any needed actions after the Add-In has done its processing but the user clicks the Close/Cancel button to delete the Calendar event. This can leave our backend system out of sync with what Outlook/Exchange is seeing.