Hillary Clinton over Email practices

Hillary Rodham Clinton speaks to the reporters at United Nations headquarters, Tuesday, March 10, 2015. Clinton conceded that she should have used a government email to conduct business as secretary of state, saying her decision was simply a matter of "convenience." (AP Photo/Seth Wenig)

In January 2011, non-government adviser providing technical support for Clinton’s email system notified her deputy chief of staff, Huma Abedin, that he’d shut down the server because he believed “someone was trying to hack us,” according to the report.

Later that day, the adviser updated Abedin with the news that “we were attacked again so I shut [the server] down for a few min.” The next day, according to the report, Abedin sent out a notice that staffers shouldn’t email Clinton “anything sensitive.”

Four months later, according to the IG’s report, two top staffers discussed — via email, it turns out — concerns voiced by Clinton herself that someone might be “hacking into her email.”

In another development Wednesday, a Romanian man known as “Guccifer” pleaded guilty in federal court to identity theft and unauthorized access to protected computers. It was Guccifer’s hacking that revealed that Clinton used a private email address in the first place.

In an earlier interview with NBC News, Guccifer claimed that he was able to breach the server and even download some files — a claim that federal investigators say they can’t substantiate.