The endpoint activation method is never called in the mailconnector example. The MDB needs to be fixed so it can perform its function as a listener. This can be done by examining (and possibly reusing) the code in the original GlassFish Samples. An explanation of endpoint activation can be found on page 16 of the white paper by Alejandro Murillo and Binod P.G. entitled "Creating Resource Adapters with J2EE Connector Architecture 1.5" circa 2004.