The property gets or set the synchronization state identifier. This property is optional with caveats. This is a read/write property.
Assembly: EWS (in EWS.dll)
The property contains a string that represents the synchronization state identifier. This identifier represents a type of watermark that describes which folders have been changed since the last synchronization. This property is optional when the first synchronization call is performed. The first call returns a SyncState in the response. The returned SyncState is used in later SyncFolderHierarchy calls to synchronize the set of changes that occurred since the last synchronization call. Therefore, the property is required for incremental synchronization calls.
If this property is set with an invalid string, an ErrorInvalidSyncStateData error may be returned.