"Still, Clinton has insisted that what she did was legal, and on Sunday she reiterated that her use of the server was a matter of convenience.
"It was already there," she said of the server. "It had been there for years. It is the system that my husband's personal office used when he got out of the White House. And so it was sitting there in the basement. It was not any trouble at all."
Clinton's unusual email system was originally set up by a staffer during Clinton's 2008 presidential campaign, replacing a server used by her husband, former President Bill Clinton."
https://www.businessinsider.com/hillary-clinton-on-her-private-email-server-i-had-little-to-do-with-it-2015-9?op=1