NBA commissioner Adam Silver says Knicks owner James Dolan is a "consummate New Yorker" and therefore will not be punished for an

angry email he recently sent to a fan.

“Jim is a consummate New Yorker,” Silver told the New York Post. “Jim got an unkind email and responded with an unkind email.”

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Dolan responded aggressively to an email from longtime Knicks fan Irving Bierman, 73, who expressed his displeasure over the team's downward spiral.

Dolan called Bierman an "alcoholic" and told him to go root for the Nets, among other insults.

"You are a sad person," Dolan wrote in the email. "Why would anybody write such a hateful letter. I am just guessing but ill bet your life is a mess and you are a hateful mess. What have you done that anyone would consider positive or nice. I am betting nothing.

"In fact ill bet you are negative force in everyone who comes in contact with you," Dolan went on. “You most likely have made your family miserable. Alcoholic maybe. I just celebrated my 21 year anniversary of sobriety. You should try it. Maybe it will help you become a person that folks would like to have around."

The Knicks, at 10-41, are in the midst of their worst season in franchise history.