It seems to me, and has the appearance, that is she was the Secretary of State and from her own rule book wrote emails to people of sensitive nature, that THIS email, a directive from her, BECOMES classified information. So, that fact that she wrote sensitive information in an email, her POST as Secretary of State it does seem should be marked CLASSIFIED when she hits the SEND key.
The Clinton Family SLUSH FUND emails will sink her, if they are ever found!!