PAJ- Ray Johnson-how to (not) answer a letter

So I was digging through some old boxes of books the other day and found a few copies of the PAJ(performance and art journal).  I started reading an article about the artist Ray Johnson, a man who is often thought of as the father of "mail art", and a frontier of "communication art".  The author of the article (Blom) examines a letter of sociably respectable letter gratitude from a recipient (St. Aubyn) of  a piece of art that Johnson had sent him. The letter's tone was stereotypical of how one is expected to react to receiving a piece of art as a "gift".  A piece or art is supposedly invaluable and therefore released of the same monetary value as many other gifts. (this is debatable .. another day)However Johnson had sent out 200 of his artworks to 200 individuals via the U.S. postal system.  It is in the exchange through the u postal system that the relationship between the artist and the receiver bend the socially acceptable rituals of art "giving".  Johnson after receiving the letter from St. Aubyn, writes his comments and  almost mocks the letter.  Writing between the lines, Johnson mocks, and makes sly yet interesting comments on St. Aubyn's letter.  Then, Johnson forward the edited letter to a friend, Bill Wilson .  This opens up the letter to a third party which then instigates a network.... hmm mail art.