"Jim is a consummate New Yorker," Silver said. "Jim got an unkind email and responded with an unkind email."
"I am utterly embarrassed by your dealings with the Knicks," the fan wrote in a message obtained by Deadspin.
Dolan responded by calling the fan "a sad person," adding "You most likely have made your family miserable." Dolan, who is himself a recovering drug addict and alcoholic, speculated that the fan might have a drinking problem. He also told the fan, who says he's rooted for the Knicks since 1952, to start supporting the crosstown Nets.
Dolan has been the majority owner of the franchise since 1997, when it was purchased by Cablevision, the telecommunications company Dolan inherited from his father.
Dolan, 59, replaced his father, Charles, as CEO of Cablevision in 1995. He also owns Madison Square Garden, the NHL's New York Rangers and MSG Network, which broadcasts Knicks and Rangers games.
The Knicks have the worst record in the NBA at 10-41.
- Dan Gartland