Mechanisms for operating in recovery mode while ensuring reliable message processing for messages received during the recovery operation mode. Upon receiving a message corresponding to a particular message transaction, the instance responsible for that message transaction determines from state information corresponding to the transaction, whether or not that instance is operating in normal mode, or recovery mode. If the state information reflects normal operation mode, then the instance processes the message. If recover mode, then the instance evaluates whether or not the message is a normal message suitable for normal operation mode, or a recovery message suitable for recovery operation mode. If the message is a normal message, then the message is placed in a persistent queue for later processing. If the message is a recovery message, the message is processed. Upon completion of recovery, the normal message in the queue may be processed.