All politics aside, the Hillary Clinton email issue raises interesting FOIA issues. As this Politico article discusses, the Republican National Committee has a request for a number of emails sent by State Department aides of former Secretary Clinton. The number of responsive documents is enormous and according to the State Department would take years to process.
Thus, how to process giant requests without harming those requesters who have standard size requests which already are not done anywhere close to the statutory time period? It has been and remains an issue within the FOIA community. In the case of the Clinton aide emails, State has attempted to get a drawn out schedule to process the material and seek a narrowing of the request from the requesters. It's ironic that both the State Department and the Republicans have failed to properly seek to fund FOIA operations for years.
Irony aside, it seems to me that in cases where there are huge amounts of records, agencies should seek special funding and take these out of the FOIA process altogether - they can then process these records under FOIA guidelines but in a parallel office that doesn't affect the other FOIA requests sought at the agency. This was done at the FBI for JFK documents in the 1990's and was similarly done at the IRS for congressional subpoena's on the tax exempt organizations issue. In other words, agencies need to think outside the box when confronted with large requests.