encountered which cannot be thrown in the thread that is calling the <tt>send</tt> method then the Jakarta Messaging provider must
 call the <tt>CompletionListener</tt>'s <tt>onException</tt> method. In both cases if an exception occurs it is
 undefined whether or not the message was successfully sent.

 <p>
 <b>Message order</b>: If the same <tt>MessageProducer</tt> is used to send multiple messages then Jakarta Messaging message
 ordering requirements must be satisfied. This applies even if a combination 