NONE of those previous Secretary's set up their own private server, and any emails sent were few and not exclusively on their private server....it's not nearly the same to compare
Hillary Clinton's exclusive use of a non-government email account to send messages to her staff during her time as Secretary of State is a break from what other top officials have done, raising concerns from both Democrats and Republicans about the propriety of the practice.
Aides to former Secretary of State Condoleezza Rice and former President George W. Bush said neither official routinely sent e-mails to staffers while they held those posts. Rice "did not use her personal e-mail for official communication as Secretary" and instead exclusively used her State Department account, according to a top aide who did not want to be quoted publicly.
Attorney General Eric Holder regularly uses his government account, according to spokesman Brian Fallon, as does Valerie Jarrett, one of President Barack Obama's top advisers.
As Clinton aides have noted, Colin Powell did regularly use a personal e-mail account while Secretary of State.
A Powell aide confirmed that information, saying, "General Powell used a personal email account during his tenure as Secretary of State. He was not aware of any restrictions nor does he recall being made aware of any over the four years he served at State."
"There is shock at what Secretary Clinton did because the most likely explanation of her intent seems clear ? she created a system designed to avoid accountability, potentially in violation of the law," said John Wonderlich, policy director of the non-partisan Sunlight Foundation.
http://www.nbcnews.com/politics/elections/hillary-clintons-personal-email-use-differed-other-top-officials-n316611