[ebxml-msg] Reliable Messaging question

Section 7.5.2 in Draft version 2.0 describes Receiving Message 
Behavior under the ebXML Reliable Messaging Protocol. It does not mention 
anything about error handling.

 

Suppose the received message is erroneous (e.g., some elements 
in the message are inconsistent with the CPA), the receiver is obligated to 
return an Error message. It is not clear to me if an Acknowledgment MUST also be 
included in the Error message.

 

Does the Error message serve as an implicit Acknowledgement? 
Will the sender keep retrying until it gets back an Acknowledgment (i.e., as 
long as the number of allowable retries have not been exhausted)?

 

Thanks,

-Arvola