If she set it up to avoid FOIA, then that would push the situation she created into the criminal realm. If it was just for convenience reasons, then it's probably not criminal. BUT, and this seems to be what you have issue with, despite her actions not being criminal, they ARE often subject to security and administrative sanctions. This isn't my opinion. It's Comey's:
"To be clear, this is not to suggest that in similar circumstances, a person who engaged in this activity would face no consequences. To the contrary, those individuals are often subject to security or administrative sanctions. "
But again, we're not talking about imposing security and administrative sanctions here. After all, she's not in the position any more. So at best she walks away with no punishment at all.. At worst, she's promoted to president.