Anyone who works with ‘sensitive’ information knows what is classified, by it’s nature.
And if in doubt, classify it temporarily.
I agree that hillary wouldn’t know (anything).
Anyone who has ever used government email also knows it doesn’t exactly classify itself other than ‘unclassified’. Which simply means it hasn’t been given a classification yet. That does NOT mean ‘non-classified’. Everyone is also given training annually instructing everyone items can later receive a classification depending on their contents and you have to treat it as such.