In a response to an email from Irving Bierman, who criticized Dolan's ownership and management of the team, the embattled Knicks owner suggested that Bierman is "an alcoholic" and told him to "start rooting for the Nets because the Knicks don't want you."
Silver commented on Dolan's email Monday, one day after the contentious exchange surfaced.
"Jim is a consummate New Yorker," Silver told the Post. "Jim got an unkind email and responded with an unkind email."
Reached via phone by ESPNNewYork.com's Ian Begley on Monday night, Bierman, 73 said he didn't want to discuss his feelings on Silver's decision in detail.
"The intention of my email was only as a disgruntled fan," Bierman said.
Sources with knowledge of the NBA's decision told Begley that Dolan's remarks did not broach territory that would cause the league to insert itself. That territory includes the use of vulgarity or any comments addressing class, race or sexual orientation.
Bierman had earlier told ESPN he emailed Dolan because he was upset over his handling of the Knicks, whom he has rooted for since 1952.
"I just felt enough is enough is enough," Bierman said.
In his initial email, Bierman wrote that he is "utterly embarased by your dealings with the Knicks" and accused Dolan of "a lot of utterly STUPID business things with the franchise." Bierman also requested that Dolan sell the team.
In his response, Dolan called Bierman "a sad person."
"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," Dolan wrote. "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. 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. In the mean while start rooting for the Nets because the Knicks dont want you. Respectfully James Dolan."
The Knicks have mostly struggled during Dolan's tenure as owner, which began in 1999. They have won just one playoff series in the past 14 years. This season, New York is 10-41.
ESPN.com's Ian Begley contributed to this report.