From James Comey's report in July: "Separately, it is important to say something about the marking of classified information. Only a very small number of the e-mails containing classified information bore markings indicating the presence of classified information. But even if information is not marked “classified” in an e-mail, participants who know or should know that the subject matter is classified are still obligated to protect it."
Clearly, Clinton's handling of marked classified information and highly sensitive information, contrary to her claim,  was contrary to the law and not in the best interests of the country. She should have been charged so as to let the matter be sorted out publicly.