PR_MESSAGE_FLAGS is one of the common message properties that indicate the current state of the message as set by the IMAPIProp::SetProps method (not the IMAPIProp::SaveChanges method). The following table defines the message states represented by the bits of PR_MESSAGE_FLAGS.
Interpretation of PR_MESSAGE_FLAGS Bits
| Bit | Constant | Meaning |
|---|---|---|
| 0 | MSGFLAG_READ | If set, indicates that the message has been transferred because the gateway has taken responsibility for the message. Applies only to outgoing messages. This flag is set by calling the IMessage::SetReadFlag method. |
| 1 | MSGFLAG_UNMODIFIED | If set, indicates that the message has not been modified since being received. |
| 2 | MSGFLAG_SUBMIT | If set, indicates that the message is marked for transfer to the Microsoft Exchange Server system because the IMessage::SubmitMessage function has been called for this message. |
| 3 | MSGFLAG_UNSENT | If set, indicates that the message is being created. |
| 4 | MSGFLAG_HASATTACH | If set, indicates that the message has at least one attachment. |
| 5 – 31 | Reserved. Do not change. |