Turns out, Barack Obama knew all along.

According to the inspector general report, President Obama was one of 13 select individuals who had "direct contact" with Hillary Clinton on her private email account.

Absolving the former president, at least somewhat, intelligence analysts determined none of Obama's correspondence with the then-Secretary of State contained classified information.

However, Obama said in an interview with CBS News in 2015 that he learned about Hillary's private server and potential misuse of top-secret intel about "the same time everybody else learned it, through news reports." (Fox News)

Press Secretary Josh Earnest acknowledged shortly after those remarks attracted attention that Obama and Clinton did exchange emails.

"The president, as I think many people expected, did over the course of his first several years in office, trade emails with the secretary of state," he said. 

...

Elsewhere in the IG report, the IG asked investigators why they made no effort to obtain the personal devices that Clinton’s senior aides were using at the State Department, since those devices were "potential sources of Clinton's ... classified emails" or places where unauthorized classified emails were being stored.

In response, officials on the probe claimed that "the culture of mishandling classified information at the State Department" was so pervasive that it "made the quantity of potential sources of evidence particularly vast" -- a rationale that the IG implied was unconvincing, because investigators could simply have obtained personal devices for a handful of key Clinton aides.