In Clinton’s FBI interview on this day, she is asked for her opinion on more than a dozen specific emails from her time as secretary of state. For just one of the emails mentioned in the FBI’s summary of her interview, the date of the email is redacted. This would indicate it is an email deemed “top secret” or above top secret, because only the dates of such emails have remained classified.
Clinton’s response about the email is also heavily redacted in the FBI’s summary. But it is mentioned that Clinton claims she doesn’t remember the email. Also, she is asked about a comment made by the man who sent her the email in which he wrote “let me know what you can via this channel.” That would suggest whoever wrote the email didn’t mind using private email matters to discuss top secret information, which would be why the FBI would ask about this email and that particular comment.
According to the later FBI summary, Clinton said that this was “representative of the emphasis he placed on handling information appropriately. Clinton had no concerns the displayed email contained classified information.” (Federal Bureau of Investigation, 9/2/2016)