For instance, in June 2009, top Obama strategist David Axelrod corresponds with Clinton at her private email address. On September 5, 2009, White House chief of staff Rahm Emanuel asks Clinton aide Huma Abedin for Clinton’s email address and is given it.
President Obama also occasionally emails Clinton. However, Obama will later claim that he was unaware Clinton was using a private server, and no evidence has yet emerged that anyone else in the White House knew about the server. (The Associated Press, 6/30/2015)