This realization comes due to a request for her emails by the House Benghazi Committee. Current Secretary of State John Kerry resolves to find the Clinton emails as soon as possible, and department officials privately reach out to Clinton’s staff starting that same month.
An email from Clinton’s former chief of staff Cheryl Mills to Kerry’s chief of staff David Wade on August 22, 2014 shows the request for Clinton’s emails begins in July. In the email, with the subject “following up,” Mills writes, “I wanted to follow up on your request last month about getting hard copies of Secretary Clinton’s emails to/from accounts ending in ‘.gov’ for her tenure at the Department. I will be able to get that to you, to the best of its availability. Given the volume, it will take some time to do but I wanted to let you know that I am working to get it to you.”
However, the Department will be forced to make a formal request for the emails in late October 2014 after none of them have been handed over. (The Washington Post, 3/27/2016) (The New York Times, 3/5/2015) (Politico, 2/16/2016)