Former U.S. Secretaries of State Colin Powell (L) and Hillary Clinton (R) listen to remarks at a groundbreaking ceremony for the U.S. Diplomacy Center at the State Department in Washington September 3, 2014. Jonathan Ernst/Reuters The top Democrat on the House Oversight committee has released a 2009 email exchange in which former Secretary of State Colin Powell advised Hillary Clinton on the use of personal email.

The exchange occurred two days after Clinton was sworn in as secretary of state.

Powell wrote that he had "a personal computer that was hooked up to a private phone line ... so I could communicate with a wide range of friends directly without it going through the State Department servers."

Powell said he "even used it to do business with some foreign leaders."

Democratic Rep. Elijah Cummings of Maryland released the email on the eve of a House Oversight hearing in which Republicans are expected to focus on Clinton's use of a private email server.