It's my understanding that the emails Clinton sent to other employees within the agency were automatically captured on the States IT system. Which means the State Department had most of her emails all along.
From a March 2015 State Department daily press briefing....
MS. HARF: First, the notion that the Department didn’t have the content of these emails until she turned them over isn’t accurate. A vast majority of them were to or from State.gov addresses or to addressees. So they were obviously retained and captured in that moment. So that notion is just not accurate and I wanted to put that out there first.
A couple other points: There was no prohibition on using a non-State.gov account for official business as long as it’s preserved. So obviously, that’s an important piece of this. When in the process of updating our records management – this is something that’s sort of ongoing given technology and the changes – we reached out to all of the former secretaries of state to ask them to provide any records they had. Secretary Clinton sent back 55,000 pages of documents to the State Department very shortly after we sent the letter to her. She was the only former Secretary of State who sent documents back in to this request. These 55,000 pages covered her time, the breadth of her time at the State Department.....
QUESTION: Yeah, but on – in June 2011, Jay Carney said from the podium, quote: “We are definitely instructed that we need to conduct all of our work on government accounts as part of the Presidential Records Act.” So how do you square those --
MS. HARF: Well, those are different things. That’s the instruction, but there is no prohibition on using a non-state.gov account for official business as long as it’s preserved. That’s in – yes. Let me finish, Justin, and then you can, I’m sure, disagree with what I’m saying and ask more questions. So there was – I mean, the fact is there was no prohibition on this happening as long as it was preserved. I would point out that she has sent in those 55,000 pages. Those are now all part of the permanent record, a vast majority of which already was, given most of it was to and from state.gov addresses......
QUESTION: Is there a prohibition now on using a personal address for government --
MS. HARF: Not to my knowledge, no. The rules as they stand now – and let me just pull this up so I have this – and NARA has continually updated their guidance. The September 2013 NARA guidance is that if an employee uses a personal email account to conduct official business, he or she is instructed to take steps to ensure that any records sent or received are preserved – for example, by forwarding it to an official government account. Those rules have been sent to all State Department employees to make sure they knew that. And again, this is an ongoing process to update records management. As you can all imagine, this is a huge undertaking for an organization as large as ours that actually hasn’t had email for – in the grand scheme of things – all that long......
MS. HARF: I can check. There – I do know, though, relatedly, that there was no real-time preservation requirement. The requirement is just to preserve any records that are part of the official record, which she has done by providing them.
Daily Press Briefing - March 3, 2015
After requesting that all former heads of state turn over all their work related records....Hillary was the only one that complied. Henry Kissinger didn't turn over all his records until recently and he had been keeping them in house all those years.