There are several message properties that have a specific meaning when they are sent to a foreign queue. The following table lists these properties and provides a brief description of any special circumstances.
| Property | Description |
| PROPID_M_ADMIN_QUEUE | Needed for acknowledgments and computing the digital signature for the message. |
| PROPID_M_APPSPECIFIC | Needed for computing the digital signature for the message. |
| PROPID_M_BODY | Specifies message. Needed for decrypting private (encrypted) messages and computing the digital signature for the message. |
| PROPID_M_CONNECTOR_TYPE | Specifies the connector that was used to send message to MSMQ. Not used when sending messages to foreign queues. |
| PROPID_M_CORRELATIONID | For acknowledgment messages, specifies the message identifier of the original message. Also, needed for computing the digital signature for the message. |
| PROPID_M_DEST_SYMM_KEY | Needed for decrypting private (encrypted) messages. When messages are sent to MSMQ queues, the symmetric key is ignored if a connector is not specified. |
| PROPID_M_DEST_SYMM_KEY_LEN | Needed for security. Specifies the length of the symmetric key. |
| PROPID_M_ENCRYPTION_ALG | Needed for security. Specifies the encryption algorithm used to encrypt the symmetric key. |
| PROPID_M_EXTENSION | Specifies any foreign message properties that have no counterpart in MSMQ. MSMQ includes this property when returning acknowledgment messages. |
| PROPID_M_EXTENSION_LEN | Specifies the length of the foreign message properties. |
| PROPID M HASH ALG | Needed for security. Specifies the hash algorithm used when authenticating messages. |
| PROPID_M_LABEL | Needed for computing the digital signature for the message. |
| PROPID_M_PROV_NAME | Cryptographic provider needed to verify signature. |
| PROPID_M_PROV_TYPE | Cryptographic provider needed to verify signature. |
| PROPID_M_RESP_QUEUE | Needed for computing the digital signature for the message. |
| PROPID_M_SENDER_CERT | Includes public key. |
| PROPID_M_SIGNATURE | Signature of sender. |