In 1970, a 21-year-old heir to a margarine fortune became a nationwide sensation when he vowed to give away his money to anyone who needed it. Michael Brody was deluged with thousands of letters, most of which sat unopened for decades, until documentarian Keith Maitland and his team decided to read them. “We started researching people, and we started tracking them down,” Maitland says. “And over and over, we kept discovering that almost nobody remembered having written these letters.” Director Keith Maitland and Executive Producer Ed Pressman talk about exploring a strange, poignant, and all but forgotten story with the film “Dear Mr. Brody.”