The PROPID_Q_QUOTAproperty is typically set when calling MQCreateQueue.

To set the maximum size when creating the queue, specify PROPID_Q_QUOTA in the MQQUEUEPROPSstructure and call MQCreateQueue.

When the quota of a queue is reached, a negative acknowledgment message is returned to the administration queue of the sending application to indicate that the queue is full.

MSMQ continues to send negative acknowledgments until the cumulative size of messages in the queue drops below the quota.

To change the maximum size of a queue, specify PROPID_Q_QUOTA in the MQQUEUEPROPSstructure and call MQSetQueuePropertieswith the new value.

When the quota of the queue is changed, the new quota affects only arriving messages; it does not affect messages in the queue.

To retrieve the maximum size of a queue, specify PROPID_Q_QUOTA in the MQQUEUEPROPSstructure and call MQGetQueuePropertiesand examine its returned value.

The following examples show how PROPID_Q_QU0TA is specified in the MQQUEUEPROPSstructure for setting and retrieving the maximum size of the queue.

To set the maximum size of the queue

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aPropID[i] = PROPID_Q_QUOTA; // Property identifier aVariant[i].vt = VT_UI4; // Type indicator aVariant[i].ulVal = 1000; // Maximum size of the queue i++;

To retrieve the maximum size of the queue

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aPropID[i] = PROPID_Q_QUOTA; // Property identifier aVariant[i].vt = VT_UI4; // Type indicator i++;

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