Updated: July 19, 2016

Applies To: Windows 10, Windows 7, Windows 8, Windows 8.1, Windows Server 2008, Windows Server 2008 R2, Windows Server 2012, Windows Server 2012 R2, Windows Server Technical Preview, Windows Vista

The PROPID_M_CONNECTOR_TYPE property specifies a connector application identifier. This property is set when some message properties that are typically set by Message Queuing were set by the sending application.

Typically, this property is set by connector applications and applications sending application-encrypted message.

Property ID


Type Indicator




Pointer to a connector application identifier.

PROPID_M_CONNECTOR_TYPE is required whenever an application sets a message property that is typically set by Message Queuing. It is typically used in the following two cases.

Whenever a connector application sends a message to a Message Queuing queue, the connector type property is required so that the receiving applications know how to interpret the security and acknowledgment properties of the messages.

Whenever an application sends an application-encrypted message, the connector type property is required so that the Message Queuing runtime knows to use the symmetric key provided in MSMQMessage.DestinationSymmetricKey to decrypt the message.

The sending application must set PROPID_M_CONNECTOR_TYPE when it sets any of the following properties. If PROPID_M_CONNECTOR_TYPE is not set, these properties will be ignored:







To specify a connector type, include PROPID_M_CONNECTOR_TYPE in the MQMSGPROPS structure and then call MQSendMessage.

To retrieve the connector type specified by the sending application, include PROPID_M_CONNECTOR_TYPE in the MQMSGPROPS structure, then call MQReceiveMessage or MQReceiveMessageByLookupId and examine the returned values.

System_CAPS_ICON_note.jpg Note

Message Queuing does not support this property in SRMP messages.

Equivalent COM Property

With COM components, the equivalent property for specifying and retrieving a connector application identifier is MSMQMessage.ConnectorTypeGuid.

For information onSee
Connector applicationsConnector Services
Sending a symmetric key when encrypting messagesApplication-Encrypted Messages

The following code fragment shows how PROPID_M_CONNECTOR_TYPE is added to arrays that can be used to initialize an MQMSGPROPS structure.

CLSID guidConnectorType = 0;                // Or the value being set  
aMsgPropId[i] = PROPID_M_CONNECTOR_TYPE;    // Property ID  
aMsgPropVar[i].vt = VT_CLSID;               // Type indicator  
aMsgPropVar[i].puuid = &guidConnectorType;  

Message Properties