In the Mailer Archive at the Harry Ransom Center of the University of Texas, there are 222 boxes of his correspondence, each holding about 190 letters, or a total of 42,000 letters. They run from the late 1930s to about 2005, about 70-years worth. It is one of the largest major author correspondence collections in the world. The letters vary in length, of course, running from one sentence to 4,000 words. On average, they are about 500 words in length and so the total runs to 20 millions of words. It took me five years to read them all once and to read 3,500 of them four or more times.