By Tom LoBianco CNN

WASHINGTON (CNN) -- The FBI released Friday nearly 200 pages of notes from its investigation of Hillary Clinton's private email server, just three days before she squares off against Donald Trump in the first presidential debate.

The notes, taken from interviews of top Clinton aides, supporters and others, include details of how a close Clinton confidant explained how the State Department made sure the White House system would not bounce back the emails from the then-secretary of state.

But the documents -- a summary of which had already been released in the overall FBI report -- provide little in the way of major bombshells.

Politically, however, Friday's release helps keep the issue relevant before the debate. The release also comes hours after news that top Clinton aide Cheryl Mills had obtained a limited immunity deal from the FBI in order to cooperate with its investigation.

In one exchange, an unidentified interviewee details alleged efforts by a top State Department official, Patrick Kennedy, to argue during the release of the Clinton emails for classifications that would protect her. But Kennedy, in his own interview, denied the charge.

Top Clinton aide Huma Abedin, in her interview, explained how they had to update email addresses with the White House so Clinton could email President Barack Obama because the President could only receive emails from approved addresses. If her email was not on an approved list, which was managed by the President's staff, the White House server would reject it. When Abedin was shown a 2012 email exchange, she did not recognize the pseudonym -- when agents explained it was Obama, she replied, "How is this not classified?"

There is no evidence Obama knew that Clinton was using a private email server at the time. He has said he only found out about her use of it when it became public. Many of those who communicated with Clinton have told the FBI they didn't realize she was using a private server, and often one may not realize what email address is behind a name unless one clicks on it.

Agents also interviewed "Guccifer" -- the hacker who targeted the Bush family -- who detailed his successful infiltration of close Clinton friend Sidney Blumenthal's email account and reviewed 30,000 emails and downloaded 25 attachments. Guccifer also detailed taking a screenshot of one Blumenthal exchange regarding the Benghazi attacks.

In other interviews released Friday evening, Clinton aides seemed generally unconcerned about her use of a private email server and said she adhered to standard security measures -- arguments they have made extensively in public. But one IT worker took a somewhat cavalier attitude, joking in one interview that a new 60-day retention policy was a "Hillary coverup operation" -- which sparked the Trump campaign's anger.

"The fact an IT staffer maintaining Clinton's secret server called a new retention policy designed to delete emails after 60 days a 'Hillary coverup operation' suggests there was a concerted effort to systematically destroy potentially incriminating information," Trump spokesman Jason Miller said in a statement. "It's no wonder that at least five individuals tied to the email scandal, including Clinton's top State Department aide and attorney Cheryl Mills, secured immunity deals from the Obama Justice Department to avoid prosecution."

The latest revelations in the Clinton email scandal are certain to play a central role in Trump's line of attack Monday, when the two meet for their first presidential debate in New York. Trump has built his "Crooked Hillary" line of insults off arguments stemming from her emails.

The additional notes were released three weeks after the FBI released its report from its investigation of Clinton and her emails, as well as the notes from Clinton's own high-profile interview with federal agents.

Clinton, in her interview, said she did not know about key records retention policies and whether she was violating rules. But on the trail, her campaign and supporters have routinely said she did not break any laws with her email handling.

No criminal charges

FBI Director James Comey in July took the unprecedented step of announcing in a press conference the FBI's conclusion that there was not enough evidence to merit a criminal prosecution, before handing over his findings to the Justice Department.

The DOJ followed that recommendation and decided no prosecution was merited.

After Comey testified about the decision before Congress, members requested access to his agency's report. Last month, the bureau gave members of Congress access to the notes, as well as notes from interviews with other Clinton staff and aides, but kept that version of the report classified.

Comey testified that no transcript of the interview exists, only the notes taken on it. Clinton was not under oath.

CNN's Laura Koran, Evan Perez, Adam Levine, Mary Kay Mallonee, Ross Levitt, Ryan Browne, Tal Kopan, Pamela Brown, Daniella Diaz and Kevin Liptak contributed to this report.

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