Commissioner Mike Slive said on Monday in a statement released by the league that Mullen violated the SEC code of ethics.
On Sunday, Mullen said the replay official who worked the Bulldogs' 29-19 loss to Florida should be disciplined for not overturning an interception return for a touchdown in the fourth quarter by Gators linebacker Dustin Doe, who might have fumbled before reaching the goal line.
"I don't even know why we have replay right now in the Southeastern Conference if they're not going to utilize it," Mullen said.
The replay official listed for the game in Starkville on Saturday night was Dan Dembinski.
"I hope he's severely punished if he ever works another SEC game again, because I think it's completely unacceptable," Mullen said.
The league's response to the Bulldogs request to review the play was to refer to Rule 12-1-2 in the NCAA football rule book, which states:
"The instant replay process operates under the fundamental assumption that the ruling on the field is correct. The replay official may reverse a ruling if and only if the video evidence convinces him beyond all doubt that the ruling was incorrect. Without such indisputable video evidence, the replay official must allow the ruling to stand."
The SEC said it would not comment further on the call.
Mississippi State spokesman Joe Galbraith said Mullen would have no comment on the SEC's actions.
Volunteers coach Lane Kiffin was also reprimanded by the conference Monday.
Kiffin, who has been reprimanded once before, was warned by Slive that further violations of SEC policies will subject the coach to additional penalties, including suspension, after he criticized officials who worked the Volunteers' game Saturday against Alabama.
Information from The Associated Press was used in this report.