Hillary Clinton checked every box for a violation of the Espionage Act. So much so that, in giving her a pass, the FBI figured it better couch her conduct as "extremely careless," rather than "grossly negligent." The latter description was stricken from an earlier draft of then-director James Comey's remarks because it is, verbatim, the mental state the statute requires for a felony conviction. It wouldn't do to have an "exoneration" statement read like a felony indictment.
In point of fact, the careless/negligent semantic game was a sideshow. Mrs. Clinton's unlawful storage and transmission of classified information had been patently willful.