Although the White House has strict requirements dating back two decades that every email must be saved, there is no such requirement for federal agencies. Instead they are in charge of setting their own policies for determining which emails constitute government records worthy of preservation and which ones may be discarded.

“It really is chaos across the government in terms of what agencies do, what individuals do, and people understand that they can decide what they save and what they don’t,” said Patrice McDermott, the director of the transparency watchdog group OpenTheGovernment.org. “If you leave it up to the agency, some are going to behave properly and take it seriously, and some are going to see it as carte blanche to whitewash the record.”

What is clear is that email poses a unique problem for government agencies, which are required under the law to preserve anything that relates to official business. “It doesn’t matter on what medium or in what form it occurs,” said Gary M. Stern, the general counsel for the National Archives and Records Administration, the agency in charge of preserving federal documents.

But, he said, “there’s such a challenge with email, because everyone gets a couple of hundred a day and nobody has the time to go through and say, ‘Is this a record, or is it not?’’’

While many agencies’ current practice is to print and file emails deemed worthy of saving, an Obama administration directive in 2012 mandates that agencies must devise a system for retaining and preserving email records electronically by the end of 2016.