Pen pal

Pen pals are people who regularly write to one another, historically by postal mail, in a relationship based primarily or solely on the exchange of letters. Pen pals are usually strangers whose relationship rests on that correspondence, though occasionally the correspondents already have a relationship that is not otherwise conducted in person. This description is adapted from Wikipedia contributors under CC BY-SA 4.0; changes were made. https://creativecommons.org/licenses/by-sa/4.0/