The broad range of information that was deemed classified by the State Department -- just within the emails published by the agency to date --underscores concerns that sensitive material was routinely mishandled on Clinton's private email server.
For example, Huma Abedin, Clinton's former deputy chief of staff, forwarded a summary of a high-level Sept. 2009 meeting to Clinton in which she detailed the "embassy security issues" that were discussed.
The issues had been raised by Eric Boswell, a diplomatic security official who was later forced to resign in the wake of the 2012 terror attack in Benghazi.
Abedin was frequently involved in the transmission of classified information to Clinton, emails show. Cheryl Mills, Clinton's former chief of staff, and Jake Sullivan, former director of policy planning, also routinely sent or received classified emails from the secretary of state.
Despite her campaign's claims that Clinton was simply a "passive recipient" of classified information, a review of her emails indicates she wrote messages that are now classified.
For example, in July 2009, she discussed relations with Russia and Afghanistan with then-Deputy Secretary William Burns in an email that has been partially classified. She also discussed her travel plans with Burns over the private network.