All the replies so far are missing the point: it is prudent to monitor for unusual events, including previously-unseen messages, over and above the explicit han

All the replies so far are missing the point: it is prudent to monitor for unusual events, including previously-unseen messages, over and above the explicit handling of specific errors. It is also prudent to not wait until morning to investigate. Your infrastructure probably is crap, as very few people get to build it themselves from scratch. That does not mean one should cheerfully accept additional unnecessary or pedantic complications. It would also be prudent to investigate each and every change to any of the software you use, in order to anticipate problems, but unnecessary and pedantic changes increase the burden there, as well.