I'm trying to use EWS to synchronize calendars between my SharePoint-based application and Exchange.

Reading through https://msdn.microsoft.com/en-us/library/office/dn440952%28v=exchg.150%29.aspx gives me conflicting information.

• Use an approach similar to notification-based synchronization. Because SyncFolderItem does not include any calendaring logic, use the EWS Managed API FindAppointments method, or the EWS FindItem operation with the CalendarView element to view appointments between two dates, and then call the EWS Managed API LoadPropertiesForItems method, or the EWS GetItem operation to retrieve the item properties for the calendar item.

• Do not poll using the EWS Managed API FindAppointments method, or the EWS FindItem operation with a CalendarView element.

These two points directly oppose each other. One says to use specific EWS methods, while the other says these methods shouldn't be used.

Also, even disregarding the conflict of those two points, there's no mention of how to actually sync calendar data. The biggest issue I have is that any modifications to recurring master items remove any recurrence exceptions (both in Exchange as well as in my SharePoint!). Because of this things tend to be a real mess.

Is there a clear-cut design pattern used for periodic synchronization of calendar events between Exchange and a client application?

• Edited by Bender Mateusz 22 hours 47 minutes ago