The PROPID_M_DEST_QUEUE_LEN property indicates the length (in Unicode characters) of the target queue's format name buffer.
The PROPID_M_DEST_QUEUE_LEN property is required whenever PROPID_M_DEST_QUEUE is passed as a property in MQReceiveMessage.
On input, PROPID_M_DEST_QUEUE_LEN specifies the length of the format name buffer passed in PROPID_M_DEST_QUEUE. The buffer should be large enough to hold the format name string including the null-terminating character.
On return, this property holds the length (in Unicode characters) of the PROPID_M_DEST_QUEUE format name string including the null-terminating character.
If the buffer is too small, MQReceiveMessage fails and PROPID_M_DEST_QUEUE_LEN can be used to obtain the required buffer length of the format name string.
MQReceiveMessage, PROPID_M_DEST_QUEUE