WASHINGTON — Anyone who has tried to pry information from the federal government may have been surprised on Tuesday by Hillary Rodham Clinton’s assertion that in all her emails in four years as secretary of state, she never strayed into the classified realm.

After all, a consensus among Republicans and Democrats for many years has been that the government routinely overclassifies information, reflexively stamping “secret” on mountains of documents with marginally sensitive content. The government classified more than 80 million documents in 2013, according to the Information Security Oversight Office, which publishes an annual count.

“I did not email any classified material to anyone on my email,” Mrs. Clinton said at a news conference on Tuesday at the United Nations. “I’m certainly well aware of the classification requirements and did not send classified material.”

But some secrecy experts and former government officials on Tuesday were skeptical, noting the interesting turnabout that had a former top official insisting, for once, that none of her exchanges were secret.