In SharePoint, if you delete / modify a single occurrence of a recurring calendar entry nothing is really deleted / modified - instead, a new entry is created telling SP that for a specific date the occurrence doesn't exist or has new parameters.
As such, this can be reversed by deleting the "exception" entry, thus getting the original occurrence back in the calendar.
I'm trying to achieve a similar functionality in Exchange using Exchange Web Service (EWS), but I'm having trouble figuring out how to do that.
A "Recurring Master" object (the Appointment entry that defines the recurring event) has two collections for exceptions. One contains modifications to specific occurrences (called ModifiedOccurrences) while the other contains "deletions" (called DeletedOccurrences).
The problem is that both these collections are read only. I can add elements to these lists by updating or deleting specific occurrences (which need to be downloaded separately), but I cannot make a "rollback".
Is there a way to do what I'm trying to do, or is this impossible given the functionality that EWS offers?
There is no way to do a roll back for a modified or deleted occurrence in EWS. This is consistent with the user experience in Outlook.