'Dirt by Mail' is a delivery service that enables a person to send a bag of dirt to someone they simply don't like or as a way to send a message to someone who might get a kick out of the delivery.
'Dirt by Mail' works by simply having users pay for the service and input the recipients address in order to have them deliver a small bag of dirt to them. The bag is accompanied by a business card that simply reads "You're a dirtbag," along with the company's website in order to let them know how they can go about sending a similarly scathing present to an enemy.
'Dirt by Mail' sends out packages anonymously to ensure that the insult the recipient receives won't get back to you.
'Dirt by Mail' Anonymously Sends a Bag of Dirt to Your Enemies
Michael Hemsworth — April 29, 2017 — Pop Culture
References: dirtbymail & thisiswhyimbroke