Not using email incorrectly, having incorrect information in her email. Why must the left spin everything, oh right because the truth seldom works. Bill wasn't impeached because of a BJ, he lied under oath. Mrs. Tuluza is not being investigated for using a personal server, she is being investigated for having classified information on a personal server. Which would be, and probably was, easy to hack.
So essentially, you want to prosecute her for what other people did (sent her e-mails over the wrong system) because of what other people MIGHT have done (Hacked her server if they were aware it existed).
So what did SHE actually do that was criminal? Not what other people did that might have caused inadvertant criminality on her part.
Sending and receiving TS SAP information. They have emails that show her directing her staff to remove classification markers.
BTW, do you know what General Petraeus was busted for?
Sharing his schedule with a person who was not holding a clearance.
That's about it. For that he was fined, fired, and his clearance revoked.
How bad does discussing the attack on Benghazi with foreign leaders and her daughter compare to that? How about satellite pictures in the Middle East? How about discussing removing classified markers? Some were so sensitive that they couldn't be revealed to the public, but there they were on a unsecured server for any hacker to look at.