Hillary Clinton told State Department staff not to use personal email to conduct official business, according to the FBI.
Her warning is noted in the FBI’s transcript of its July interview with the former Secretary of State regarding her own unauthorised use of a private email server containing classified information.
The FBI closed its investigation last month into whether she had abused state secrets, without recommending criminal charges.
However, it called her arrangement “extremely careless”, and the issue has dogged the Democratic White House candidate’s campaign.
The transcript notes: “In 2011, a notice to all State employees was sent on Clinton’s behalf, which recommended employees avoid conducting State business from personal e-mail accounts due to information security concerns.