So the scenario is that I\'m using an SB queue to throttle outgoing callbacks to other services. One of the standard problems with calling back to other services is that the
If you want to put a message away for a while and you have a place to write down the SequenceNumber (which might be in Session state in a sessionful queue), you can Defer() it. Deferred messages can be retrieved using a special Receive overload giving the SequenceNumber; that's also the only way to get at them again other than them expiring, so careful. This feature was built for workflows and state machines so that they can deal with out of order message arrival.