This property indicates the message type. A message can be one of the following:

• A normal MSMQ message
  
  
• A positive or negative (arrival and read) acknowledgment message
  
  
• A report message
  
  

Typically, this property is set by MSMQ when it sends the message; however, it can also be set by an MSMQ connector application when the connector application sends a message.

Type Indicator

VT_UI2 (or VT_NULL)

PROPVARIANT Field

uiVal

Property Values

Normal messages (all messages created by your application)

MQMSG_CLASS_NORMAL

A normal MSMQ message.

Positive arrival acknowledgment message (typically generated by MSMQ)

MQMSG_CLASS_ACK_REACH_QUEUE

The original message reached its destination queue.

Negative arrival acknowledgment messages (typically generated by MSMQ)

MQMSG_CLASS_NACK_ACCESS_DENIED

The sending application does not have access rights to the destination queue.

MQMSG_CLASS_NACK_BAD_DST_Q

The destination queue is not available to the sending application.

MQMSG_CLASS_NACK_BAD_ENCRYPTION

The destination Queue Manager could not decrypt a private (encrypted) message (see PROPID_Q_PRIV_LEVEL).

MQMSG_CLASS_NACK_BAD_SIGNATURE

MSMQ could not authenticate the original message. The digital signature of the original message is not valid.

MQMSG_CLASS_NACK_COULD_NOT_ENCRYPT

The source Queue Manager could not encrypt a private message (PROPID_M_PRIV_LEVEL).

MQMSG_CLASS_NACK_HOP_COUNT_EXCEEDED

The hop count of the original message is exceeded.

MQMSG_CLASS_NACK_Q_EXCEED_QUOTA

The destination queue of the original message is full.

MQMSG_CLASS_NACK_REACH_QUEUE_TIMEOUT

The time-to-reach-queue or the time-to-be-received timer expired before the original message could reach the destination queue.

For a transactional message, this is an in-doubt negative acknowledgment.

For example, the local Queue Manager sets this class when the message timer expires if even though a positive confirmation is in route from the remote queue manager.

MQMSG_CLASS_NACK_PURGED

The message was purged before reaching the destination queue.

MQMSG_CLASS_NACK_NOT_TRANSACTIONAL_Q

A transactional message was sent to a nontransactional queue.

MQMSG_CLASS_NACK_NOT_TRANSACTIONAL_MSG

A nontransactional message was sent to a transactional queue.

MQMSG_CLASS_NACK_UNSUPPORTED_CRYPTO_PROVIDER

The target Queue Manager does not have the enhanced (128-bit) cryptographic provider installed.

Positive read acknowledgment message (typically generated by MSMQ)

MQMSG_CLASS_ACK_RECEIVE

The original message was retrieved by the receiving application.

Negative read acknowledgment messages (typically generated by MSMQ)

MQMSG_CLASS_NACK_Q_DELETED

The queue was deleted before the message could be read from the queue.

MQMSG_CLASS_NACK_Q_PURGED

The queue was purged and the message no longer exists.

MQMSG_CLASS_NACK_RECEIVE_TIMEOUT

The original message was not removed from the queue before its time-to-be-received timer expired.

For a transactional message, the remote Queue Manager has indicated that the message was not retrieved. This is the only negative acknowledgment that can be trusted to indicate the message was not retrieved.

MQMSG_CLASS_NACK_RECEIVE_TIMEOUT_AT_SENDER

For transactional messages only. The local Queue Manager has indicated that the original message was not removed from the queue before its time-to-be-received timer expired.

This class is an in-doubt negative acknowledgment. For example, the local Queue Manager sets this class when the time-to-be-received timer expires even if a positive confirmation is in route from the remote Queue Manager.

Report messages (typically generated by MSMQ)

MQMSG_CLASS_REPORT

Sent each time the message enters or leaves an MSMQ server.

Remarks

Examples

This example shows how PROPID_M_CLASS is specified in the MQMSGPROPSstructure.

	Copy Code
MsgProps.aPropID[i] = PROPID_M_CLASS; //PROPVARIANT Field MsgProps.aPropVar[i].vt = VT_UI2; //Type Indicator i++;

Note:
OS versions prior to 2.12 require the MSMQ add-on pack.

Requirements

See Also