Using SimpleActionEndpointMapping results in wsa:MessageAddressingHeaderRequired errors being returned from a request unless that request specifies
a wsa:To and wsa:MessageID header. According to the WS-Addressing standard, only the wsa:Action header is mandatory.
The problem appears to lie in the hasRequiredProperties() method of org.springframework.ws.soap.addressing.MessageAddressingProperties. This method insists on
1. wsa:To being present
2. wsa:MessageID being present if either ReplyTo or FaultTo have been specified.
In the case of (2) above I was able to trigger the fault by omitting all of the MessageID, ReplyTo and FaultTo headers in my request, so it may be that the server-side stack has inserted a default "anonymous endpoint" value into one or both of the latter and that is triggering the error.