In December 2014, a hrcoffice.com domain was created on a different private server, and apparently Clinton switched to using an email account on that server around that time.
On February 22, 2016, Williams & Connolly, the law firm of Clinton’s personal lawyer David Kendall, tells the FBI in a letter: “Secretary Clinton did not transfer her clintonemail.com emails for the time period January 21, 2009 through February 1, 2013 to her hrcoffice.com account.” This time period represents Clinton’s tenure as secretary of state.
The FBI apparently trusts Clinton’s lawyer. A September 2016 FBI report will state: “The investigation found no evidence Clinton’s hrcoffice.com account contained or contains potentially classified information or emails from her tenure as secretary of state. The FBI has, therefore, not requested or obtained equipment associated with Clinton’s hrcoffice.com account.” (Federal Bureau of Investigation, 9/2/2016)