Replaces the flags of the messages specified by MessageSet with the flags specified by MessageFlags .
The 'callback' parameter specifies a function which will be called when the operation completes (or an error is encountered). If the 'callback' parameter is not specified, then the method will block and will not return until the operation completes (or an error is encountered).
The callback for this method is defined as:
'err' is the error that occurred. If there was no error, then 'err' is 'null'.
'err' has 2 properties which hold detailed information:
Examples of possible flag values are server dependent, but can include:
|\Deleted||Mark a message as deleted (for removal by later ExpungeMailbox).|
|\Seen||Mark a message as read.|
|\Answered||Mark a message as answered.|
|\Flagged||Mark a message as flagged.|
|\Draft||Mark a message as being incomplete (under composition).|