As an early and influential participant in Mail Art, Ray Johnson used the US postal system in a conceptual art practice that linked people in a wide circle of exchange. He sent objects and envelopes, sometimes with comments or instructions, to people he knew or was aware of, sometimes further implicating them in his ongoing project by asking them to send things on to specified others.

In 1962 one of his correspondents, Ed Plunkett, suggested that Mail Art might be informally incorporated as the New York Correspondence School, after the matchbook advertisements for art schools in the 1950s and 60s. Johnson changed the penultimate "e" to "a," thus Correspondence to Correspondance, to suggest movement and play. Thereafter, Johnson organized meetings of the New York Correspondance School (NYCS), gatherings in which "nothing" often happened. These later became a form of performance art in which Johnson would stage an activity before an audience.

On April 5, 1973, Johnson wrote to the New York Times notifying them of the demise of the New York Correspondance (sic). The letter was signed "Buddha University," with the monogram of a bunny head beneath it. Mail Art activities subsequently continued under various names, among them Buddha, Buddhette University, The Dead Pan Club, Blue Eyes Club, and Spam Radio Club.