Nate Jones, director of the Freedom of Information Act Project at the National Security Archive, said the time-consuming review is not without consequences. He cites State's acknowledgement that the review is consuming a major chunk of its FOIA resources, delaying other reviews—including his own group's push for more records on Henry Kissinger.
The agency has not provided an estimated cost for the review, which will have consumed more than six months if State works through January.
Clinton turned over physical copies of the messages printed from her private server in December, but the review didn't begin in earnest until months later.
A five-week scanning process was completed in May, and State estimated in mid-May that they would finish uploading the messages into a database in mid-June, according to a court filing.
The department provided National Journal with the rough salary ranges under the governmentwide "general schedule," or GS pay scale, of the 12 personnel working full-time on the review.
Their possible salaries range from a low of roughly $63,700 to a high of over $150,000. "We have the option to add or hire additional staff if necessary," the spokesman said.
So if just those dozen staffers worked on the project for seven months, the cost of that manpower alone would range from at least $445,000 to more than $1 million.
But the labor-intensive review goes well beyond those 12 staff members.
A court filing last month from a State official—part of a FOIA lawsuit from a Vice News reporter that led to the release schedule—provided a look at the inner workings of the State review, which began with an intensive scanning process.
It notes that in addition to the full-time FOIA division staff, there are "other analysts and information technology specialists who provide collateral assistance to this review in addition to their regular duties."
The document is a declaration from John Hackett, State's acting director of the Office of Information Programs and Services, who had proposed releasing all the messages early next year, but a federal judge shot down that plan and instead wants batches released every 30 days.
There's also as-needed vetting of documents by "subject matter experts," and reviews by State's Office of the Legal Adviser.
The review extends outside of State too, requiring review by other agencies in some cases, the court filing states.
The document notes that State has advised the Central Intelligence Agency, Department of Defense, Department of Justice, Office of the Director of National Intelligence, National Security Council, and the White House of the review and asked for their assistance.
The staff time devoted to the review of messages from Clinton's exclusive use of a private email server and account has drawn GOP criticism. In March, GOP Rep. Mike Pompeo told Bloomberg that "this challenge was created when a government employee decided not to use the government system."