For a scheduling message sent by an "Organizer", the server first tries to locate a corresponding scheduling object resource belonging to the "Attendee". If no matching scheduling object resource exists, the server treats the scheduling message as a new message; otherwise, it is treated as an update.
In the case of a new message, the server processes the scheduling message and creates a new scheduling object resource as per Section 4.3.
In the case of an update, the server processes the scheduling message and updates the matching scheduling object resource belonging to the "Attendee" to reflect the changes sent by the "Organizer".
In each case, the scheduling message MUST only appear in the "Attendee's" scheduling Inbox collection once all automatic processing has been done.