From the Daily Beast here:
The top aide to Secretary of State Hillary Clinton was told in late 2012 that a non-profit watchdog group had requested information about Clinton’s email, including the number of accounts she used, according to documents released Wednesday. ... [The aide] was alerted to the request, from the group Citizens for Responsibility and Ethics in Washington (CREW), via an email from a State Department spokesman, Brock Johnson, on Dec. 11, 2012. [The aide] was told that the group had filed a “significant” request seeking “records sufficient to show the number of email accounts of or associated with Secretary Hillary Rodham Clinton…” The aide, Chief of Staff Cheryl Mills, and other Clinton advisers knew at the time that the secretary was using a private email system to conduct official business. But despite the information request, the State Department told the group that it had found no “responsive” records. “This is evidence that Cheryl Mills covered up Hillary Clinton’s email system,” Tom Fitton, the president of Judicial Watch, a conservative group that sued for information about that original 2012 request, said in a statement. “She was aware of the [Freedom of Information Act] request about Clinton’s email accounts and allowed a response to go out that was a plain lie. And you can bet if Cheryl Mills knew about this inquiry, then Hillary Clinton did, too.”