This is according to a Washington Post analysis of the more than 30,000 released emails on her private server during her time as secretary of state. Clinton has maintained that while some of her emails had classified content, they were emails sent to her. While over 2,000 of those emails are classified, and thus partially or fully redacted, the names of the senders and recipients are given for each, allowing the Post to analyze them. (This does not count the 22 “top secret” emails, or the 19 emails between Clinton and President Obama, since all information about those emails is redacted.)
As secretary of state, Clinton was emailed a lot of information by her aides. Of the classified emails sent by Clinton, in many cases she wrote short commentaries on longer informative emails sent to her. In three-fourths of these 104 emails, at least some of Clinton’s comments were classified.
Clinton argues that these emails are only retroactively classified and there was considerable over classification. The State Department has largely dodged the issue, saying they have only analyzed what content is classified now, not what should have been classified then. (The Washington Post, 3/5/2016)
At least 46 of the 104 emails contain text classified as “foreign government information,” meaning information from, to, or about foreign governments. (The New York Times, 5/10/2016)