"There's not any blanket prohibition on any federal employee from using a personal email account to conduct government business," said Potomac Law Group partner Neil Koslowe, a former Justice Department special litigation counsel who has worked on cases involving the Federal Records Act.

If it turns out that Clinton destroyed documents or mishandled classified information, that would be another story -- such violations can be criminal. However, the State Department has said there are "no indications" that Clinton improperly used her email for classified information.

The New York Times on March 2 reported that Clinton relied on her personal email account exclusively when she ran the State Department between 2009 and 2013, thwarting government record-keeping procedures.

National Archives and Records Administration regulations require emails to be "preserved in the appropriate agency recordkeeping system," but when Clinton was in government there was no specified deadline for turning them over.

In 2013, David Ferriero, who heads the archives, testified before the House Committee on Oversight and Government Reform that the agency "discourages the use of private email accounts to conduct federal business, but understands that there are situations where such use does occur."

Following that hearing, according to a statement from the archives, Congress amended the Federal Records Act and the Presidential Records Act in November 2014 -- 21 months after Clinton left government -- to "prohibit the use of private email accounts by government officials unless they copy or forward any such emails into their government account within 20 days." [The National Law Journal, 3/9/15]