Here is the thing, though.  Information is not "born" classified - someone has to classify it.  There is extensive guidance given to people authorized to classify information, but one underlying principle is that "if there is significant doubt about the need to classify information, it shall not be classified".  Almost all of the e-mails in question were NOT classified at the time they were sent.  Mostly they were classified retroactively BY THE FBI.  So we have a situation where FBI investigators trying to build a criminal case are retroactively classifying e-mails, then wanting to indict someone because there is classified information present.  Talk about planting evidence!  No wonder they will never be able to build a case that would withstand scrutiny in a court of law - the judge would laugh them out of court.  Which is why they are attempting instead to prosecute the case in the court of public opinion and political partisanship where they know they will get a hearing.