I'm working on application which synchronize calendar data from exchange server to application database. For this purpose we using the ExchangeService.SyncFolderItems method from EWS managed API. On initial sync we retrieving all appointments from Exchange, save them with UniqueId to database and save sync state for calendar folder from SyncFolderItems method response. For next sync we use saved sync state for SyncFolderItems call.
Today I had found that when I accept meeting in Outlook, it returned as deleted on next sync. Also, with this deleted meeting returned new Appointment with new UniqueId value, created from accepted one.
The problem is that in application user can add some data to meetings (attach files, link items to each other etc.) and all this actions are local changes, not synchronized to Exchange.
Is there any way to detect that newly created appointment were created from deleted one to update UniqueId of meeting instance in application database instead of deleting existing meeting and adding new one?
