The current implementation only allows using the message ID as a correlation ID and having a conduitSelectorPrefix with synchronous exchanges.
Using a conduitSelectorPrefix is necessary with WebSphereMQ. See also http://cxf.547215.n5.nabble.com/JMS-Message-Correlation-in-CXF-2-3-td4830121.html
This feature has previously been implemented for CXF 2.2 in
CXF-2760 but was dropped in the transition to 2.3.