Once upon a time, when the world was less complicated, there was a little word. His name was Mail. He stood for something very useful. Every day, millions of people would evoke him in their minds and use him to send letters, packages and postcards to their loved and unloved ones across the world. Some people received love letters from him. Others received overdue bills. Some people loved him, while others reviled him. But there was one thing nobody could ever do -- ignore him. Mail was aware of his all-pervasive role in everyday life. He knew he was a four-letter word but he sure was proud of it! He served humankind like this for several centuries.
Steeped in his happy and proud life, little did Mail notice what portents Father Time was conjuring for him. There were a few hackers who went by the names of Brian Kernighan, Dennis Ritchie, Ken Thompson and Rob Pike. They worked at Bell Labs, a facility that Mail feared much as Middle Earth feared Mount Doom. Therein was forged Unix, an operating system that researchers around the world would use to collaborate. They would send messages to each other using no more than electric charges traveling in the ether. Things started to take a distinct downturn for Mail after some other hackers at Berkeley came up with the TCP/IP stack, which formed the basis of a new-fangled medium of communication known as e-mail.
Especially after the World Wide Web took off, many former patrons of Mail started to ignore him. They used his evil rival e-mail so much more that first they dropped his hyphen and started referring to him simply as email. Then the unthinkable happened! People started to use the word mail but did not evoke images of letters, parcels and postcards, but merely evanescent flashes of electricity traveling down cables much faster than the now-worn out Mail ever could.
After all his centuries of loyal service, the word Mail now started to refer to a usurper. After his evil rival email arrived upon the scene, the original Mail got morphed into a retronym. He was now considered to be so slow and decrepit that many of his patrons started referring to him as Snail Mail. He bore this label with some shame, for he was now officially retro- and therefore possibly irrelevant. He resigned himself to the hope that someday, maybe some of his patrons would cherish nostalgic memories about him.
What kept Snail Mail happy now were his many companions in the retronym world: the acoustic guitar, black and white television, manual typewriter, landline phone, Classic Coke, hard copy and the analog watch. Together, they lived somewhat happily ever after.