"Oh, for goodness, it's not going to happen. I'm not even answering that question," Clinton said in the CNN/Univision debate in Miami.
Clinton was asked by moderator Jorge Ramos about the controversy over her emails and whether she ever improperly sent classified information over her server.
The former secretary of State reiterated that her email arrangement was permitted and said the classification of her emails reflects excessive secrecy in the government.
"I think that what we've got here is a case of over-classification," Clinton said.
"I'm not concerned about; I'm not worried about it, and no Democrat or American should be, either."
Before the exchange, Ramos disclosed that his daughter works for the Clinton campaign. He then fired off a multipronged question, asking Clinton about the 104 emails she wrote that the government now says contained classified information.
He added that Clinton's email arrangement appears to contradict a memo she sent to her employees at the time directing them to use official email "precisely because of security concerns."

"So it seems that you issued one set of rules for yourself and a different set of rules for the rest of the State Department," Ramos said. "So who specifically gave you permission to operate your email system as you did. Was it President Obama?"

While saying the use of a private server "wasn't the best choice," Clinton replied that she didn't need permission. Her predecessors had done the same thing, she said.

"What you're talking about is retroactive classification," Clinton said. "Some of the parts of the government — we're not exactly sure who — has concluded that some of the emails should be now retroactively classified. They just said the same thing to former Secretary Colin Powell.

"Now I think he was right when he said this was an absurdity."

Clinton then got testy when Ramos pressed again and asked who gave her permission to operate the private email server.

"There was no permission to be asked," she said. "It had been done by my predecessors, it was permitted. I didn't have to ask anyone."
Republicans have assailed Clinton over the email server, with their leading presidential candidates suggesting repeatedly that she could face criminal charges.
Former State Department IT staffer Bryan Pagliano last week was reportedly granted immunity to testify as part of the FBI’s ongoing investigation connected to Clinton’s use of a personal server while in office.

Pagliano could give the FBI new information about how the server was installed in Clinton’s New York home and how widespread knowledge of her private email system was.

Clinton has said she is “delighted” that Pagliano is cooperating with the federal investigation and adamantly denies that she broke the law.

“I will reiterate because it’s a fact — nothing I sent or received was classified,” Clinton said Monday on Fox News.
— Updated at 9:38 p.m. Julian Hattem contributed.