Retired Army Lt. Gen. Michael T. Flynn accused former secretary of state Colin L. Powell of writing “really mean things” in his private emails late Wednesday, after Powell’s emails were leaked online and showed him lambasting Flynn as “right-wing nutty” and a poor leader before retiring.

Flynn, Republican presidential candidate Donald Trump’s top military adviser, questioned why current and former senior officials haven’t yet learned that they will be targets to hackers.

“I have said ‘I would love to have my emails hacked’ — and people, I know they have tried it — because … I’m not disparaging people in my emails,” Flynn said in an interview with Fox News’s Megyn Kelly. “I’m being very honest, very blunt. … What I say publicly is what I say in my private email communications. I don’t screw around like that because I was taught as a young kid by my father to treat others like you like to be treated. And that’s the Golden Rule.”

Powell’s emails, first reported Wednesday by BuzzFeed News, appear to confirm a number of details in a Washington Post story that was published in August and said Flynn’s boisterous partisan rhetoric has rattled or angered a number of other retired military officers. Powell, who was the Pentagon’s top general from 1989 to 1993, called Flynn a “jerk” at least once in his emails, and said he heard the retired three-star officer was forced out as the head of the Defense Intelligence Agency (DIA) in 2014.

“I spoke at DIA last month,” Powell wrote to his son, Michael, on July 19 before relaying a story he apparently heard from Marine Lt. Gen. Vincent Stewart, the current DIA director. “Flynn got fired as head of DIA. His replacement is a black Marine 3-star. I asked why Flynn got fired. Abusive with staff, didn’t listen, worked against policy, bad management, etc. He has been and was right-wing nutty every [sic] since.”

In another Powell email sent May 1 to his former chief of staff, retired Army Col. Lawrence Wilkerson, Powell said Stewart was “impressive but overwhelmed with requirements that are unconstrained and resources that are not.” Powell also went on then to describe Flynn in unflattering, if less harsh, terms.

“Predecessor Flynn, not a media darling, was smart but did not know how to bring along his leaders,” Powell wrote. “Personality.”

The leaked emails, which have been verified as legitimate by representatives of Powell, also include another Aug. 2 exchange between Powell and Harlan Ullman, a retired Navy officer and military strategist, in which Powell wrote that Flynn got “canned out of DIA.”

Powell also wrote to Ullman that a fiery speech made by retired Marine Gen. John Allen on behalf of Hillary Clinton at the Democratic National Convention was “a little over the top” and questions whether it prompted “Marty” — presumably Army Gen. Martin E. Dempsey, the previous chairman of the Joint Chiefs of Staff — to write a letter to The Washington Post that said retired military officers should avoid speaking at political conventions.

“Yes, John is so calm-like his demeanor was odd,” Powell wrote.

Powell’s emails add another element to the public reaction to the boisterous involvement of Flynn in Trump’s campaign. The retired three-star general has at various times called President Obama a liar, claimed the U.S. justice system is corrupt and said he was pushed out of his DIA job because of his views on radical Islam. Former superiors, including Director of National Intelligence James R. Clapper Jr., have been angered by his claims, The Post reported in August, citing current and former officials close to the situation.

The Post also reported then that retired Army Gen. Stanley A. McChrystal, who relied heavily on Flynn in Iraq and Afghanistan, and retired Navy Adm. Michael Mullen, a former chairman of the Joint Chiefs of Staff, have reached out to Flynn in an attempt to rein him in.

Flynn, speaking Wednesday on Fox News, sought to discredit Powell, saying he was an “amazing guy” with “amazing service,” but will always be “struggling for his credibility because of the statement he made to the United Nations that brought us into the war in Iraq.” Powell laid out the case for the invasion of Iraq in 2003, saying intelligence showed that Saddam Hussein had a weapons of mass destruction program and sought to link al-Qaeda to Iraq. He later said the speech was a “great intelligence failure” and was written by then-Vice President Richard B. Cheney’s office.

“When I think about some of the dumb decisions that have been made over the years by people who have lived in the bubble of Washington, D.C., we just can’t have that anymore and frankly what he said about Hillary Clinton, what he said about Trump, whatever,” Flynn said of Powell. “You know, I mean, at this stage we have such bigger issues to deal with in this country.”

Flynn was not asked by Kelly to comment on whether Powell’s characterization of his dismissal at the DIA was true, and Flynn has not responded to a request from The Post for an interview. Asked by Kelly if the contents of the emails being made public were extraordinary, he agreed they were and said it was “soap-opera-level stuff.”

Powell has not yet commented on the emails, their contents or the hack.