But Hillary Clinton told us over and over again that she did not send or receive classified information. So how is this even possible?
Because the contents have since been marked as such.
Incorrect. Some of the e-mails were marked classified at the time. Besides, Hillary Clinton told us at her U.N. speech that she "did not e-mail any classified material to anyone on my e-mail." Now, her campaign is admitting some information was classified, in order to tar Republicans. Go figure.
Hillary's greatest "classified" hits:
https://www.youtube.com/watch?v=rj_cn1XA888
You do know this is about the FBI transcripts and not the e-mails, right?