According to the FBI, around 2007, Justin Cooper purchased an Apple OS X server. Cooper is a personal aide to former President Bill Clinton at the time. On February 1, 2008, the domain names clintonemail.com, wjcoffice.com, and presidentclinton.com were registered, but apparently the server that uses them won’t be operational until a few months later. The server is physically located in a house in Chappaqua, New York, where Bill and Hillary Clinton live.
The server consists of an Apple Power Macintosh G4 or G5 tower and an HP printer. According to Cooper, around June 2008, an Apple employee installs the server in the basement of the Chappaqua house. Cooper is the only person with administrative access to the server. However, the Clinton family and their house staff have physical access to it.
Hillary Clinton uses her att.blackberry.net email account as her primary email address until around mid-to-late January 2009 when she will switch to a newly created email@example.com account hosted on this server. (Federal Bureau of Investigation, 9/2/2016)