So, learning about RabbitMQ when reviewing a pull request from a coworker, I catch mention of “dead letter exchange.” Surely, there must be a greater meaning behind this, and indeed there is. A dead letter office is the place where undeliverable mail without a legible return address is sent. Here is where there are detectives that try to discern information from either hints in the address labels or hints from within the mail as to where the mail should be sent. Historically, USPS was able to then deliver 40% of such mail sent to the dead letter office. The remainder would have valuables removed and later be auctioned off. It is the last part that makes the dead letter office look curiously interesting. Nowadays, USPS calls the modern equivalent the “Mail Recovery Center.”
20190206/https://en.wikipedia.org/wiki/Dead_letter_office
20190206/https://arago.si.edu/category_2032238.html
20190206/https://postalmuseum.si.edu/research/articles-from-enroute/remembering-the-dead.html
20190206/http://about.usps.com/postal-bulletin/2012/pb22351/html/info_005.htm