The replyToAddress normalized message property is required for resolving the routing of callback messages to the correct endpoint address when multiple receive or pick activities are associated with the same partner link.

This is because the BPEL process service engine only stores the replyToAddress property once when receiving a request from a partner link at the initiating receive or pick activity. The replyToAddress property routes the callback message and is not reset if a midprocess receive or pick activity is used. The replyToAddress property uses the bpelx:inputProperty extension.