The Records Act is very clear about the requirement for all government official’s official mail being archived. Especially for cabinet officers, members of the senior executive service and general officers.
The law doesn’t exist anymore.
I would bet the WH told her to do this. Obama may have been setting her up, of course, but I think it was really because he had no intention of letting her be a real Secretary of State (since one of the reasons she was always off partying in Brazil or wherever was that Obama never let her go on any serious visits, and only summoned her into the public eye when he didn’t want to take the heat for something).
He didn’t want any official connection with her and told her to set up a private account. There’s no way a Secretary of State would have done this otherwise.
She would certainly have been fine with it, of course, because the Clintons have always been weird and secretive, but also because she seems to have been genuinely intimidated by Bambi.
I think the Records Act is the tip of the iceberg. What was the content of those emails - in and out? Was any of the information classifiable? Petraeus privately sharing handwritten notebooks with classified information seen by an individual who may have had a security clearance, perhaps not for all the information potentially seen - but which went no further, was prosecuted to a plea deal.
Here, the information was electronically transmitted outside of a secure system - and hacked with some already made public. What more will the hacker release? Or otherwise get to the wrong people and result in real damage.
Find out her email and hack it.