@EddyFree
In my opinion, what she did falls under the category of "plausible deniability". The law said that all communications and records that pertain to government business must be preserved. However, by using her "private" server, we now have a situation where she gets to decide which emails are relevant and preserved. She can say that she turned over all the pertinent records, but how do we know? Since we cannot prove that she is correct or lying, she has "plausible deniability".
From CNN: A CNN reporter, citing experts, said that Hillary Clinton broke the law by using her personal email account to conduct official State Department business while she was secretary of state. "So her spokesperson says that she, while using this personal account, was adhering to the spirit and the letter of the law, but consider this: President Obama, for instance, has a government email account. This is for a couple of reasons. Because it's secure and also for the preservation of historic records. She used only her personal account, and that means she and her aides have tremendous discretion when it comes to the preservation or handing over of documents for certain things, say Benghazi or other issues where documents may be needed."
To me, this is like having Enron audit their own financial statements.