// SETUP
MockRepository mocks = new MockRepository();
IQueue mockQueue = mocks.StrictMock<IQueue>();

queue.Received+=null;//create an expectation that someone will subscribe to this event
LastCall.IgnoreArguments();// we don't care who is subscribing
IEventRaiser raiseReceivedEvent = LastCall.GetEventRaiser();//get event raiser for the last event, in this case, Received
Expect.Call(mockQueue.Send).Return(msgId);
mocks.ReplayAll();

// EXEC
Requester req = new Requester(mockQueue);

// We expect this method to send a request to the mock queue object.
req.DoSomething();
// Now we raise an event from the mock queue object.
raiseReceivedEvent.Raise(eventArgs);

// VERIFY
// we would probably also check some state in the Requester object
mocks.VerifyAll();