When Secure Easy IM requests an end-to-end session as an option to a send session, Secure Easy IM will keep the send session open requesting a response from the receiving Seim iBox. The response when received will be immediately relayed back to the original sending Seim iBox. Secure Easy IM uses the call back feature to notify Secure Easy IM that a message is pending delivery from Secure Easy IM. If the destination Seim iBox is in Instant Receive (callback) mode it will instantly retrieve the message and respond accordingly to the solicitation for a response. If no response is forthcoming, e.g. if Secure Easy IM is not in Instant Receive mode, then a failure condition is generated and returned to the original sending Seim iBox. Optionally, the originating Seim iBox can specify that in the event of a failure to get a response while on-line that a delayed response may be delivered later during normal usage.