Fired FBI chief James Comey used his private Gmail account hundreds of times to conduct government business — and at least seven of those messages were deemed so sensitive by the Justice Department that they declined to release them.

The former top G-man repeatedly claimed he only used his private account for “incidental” purposes and never for anything that was classified — and that appears to be true.

But Justice acknowledged in response to a Freedom of Information request that Comey and his chief of staff discussed government business on about 1,200 pages of messages, 156 of which were obtained by The Post.