3.1.1.3 Per Message Object
A Message object is represented by the MessageObject ADM data type. The following ADM elements are maintained for each MessageObject:
MessageObject.ReadState: A state specifying whether the message has been read by a user, as specified in section 3.1.4.10. The possible state values are as follows:
Unsent: The message has not been sent.
Read: The message has been read.
Resend: The message has been marked for resending.