The wikipedia article on Clinton’s email covers the basic sequence of events. My specific comment refers to this:
“In May 2016, the Department's Office of the Inspector General Steve Linick released an 83-page report about the State Department's email practices. The Inspector General was unable to find evidence that Clinton had ever sought approval from the State Department staff for her use of a private email server, determining that if Clinton had sought approval, Department staff would have declined her setup because of the "security risks in doing so." Aside from security risks, the report stated that she did not comply with the Department's policies that were implemented in accordance with the Federal Records Act. Each of these findings contradicted what Clinton and her aides had been saying up to that point.”