So just what was in those "top secret" emails that Hillary Clinton received on her personal email server while she was Secretary of State? The New York Times reports what everyone has already figured out: they were about drones. What's more, the question of whether they contain anything that's actually sensitive is mostly just a spat between CIA and State:
Some of the nation’s intelligence agencies raised alarms last spring as the State Department began releasing emails from Hillary Clinton’s private server, saying that a number of the messages contained information that should be classified “top secret.”
The diplomats saw things differently and pushed back at the spies. In the months since, a battle has played out between the State Department and the intelligence agencies.
....Several officials said that at least one of the emails contained oblique references to C.I.A. operatives. One of the messages has been given a designation of “HCS-O” — indicating that the information was derived from human intelligence sources...The government officials said that discussions in an email thread about a New York Times article — the officials did not say which article — contained sensitive information about the intelligence surrounding the C.I.A.’s drone activities, particularly in Pakistan.
The whole piece is worth reading for the details, but the bottom line is pretty simple: there's no there there. At most, there's a minuscule amount of slightly questionable reporting that was sent via email—a common practice since pretty much forever. Mostly, though, it seems to be a case of the CIA trying to bully State and win some kind of obscure pissing contest over whether they're sufficiently careful with the nation's secrets.
Release them all. Redact a few sentences here and there if you absolutely have to. It's simply ridiculous to have nebulous but serious charges like these hanging like a cloud over the presidential race with Hillary Clinton unable to defend herself in any way. Release them and let the chips fall where they may.