The State Department's independent watchdog has issued a highly critical analysis of Hillary Clinton's email practices while running the department, concluding that she failed to seek legal approval for her use of a private email server and that department staff would not have given its blessing because of the "security risks in doing so."

The inspector general, in a long awaited review obtained Wednesday by The Washington Post in advance of its publication, found that Clinton's use of private email for public business was "not an appropriate method" of preserving documents and that her practices failed to comply with department policies meant to ensure that federal record laws are followed.

The report says Clinton, who is the Democratic presidential front-runner, should have printed and saved her emails during her four years in office or surrendered her work-related correspondence immediately upon stepping down in February 2013. Instead, Clinton provided those records in December 2014, nearly two years after leaving office.

The report found that a top Clinton aide was warned in 2010 that the system may not properly preserve records but dismissed those worries, indicating that the system passed legal muster. But the inspector general said it could not show evidence of a review by legal counsel.

The 83-page report reviews email practices by five secretaries of state and generally concludes that record keeping has been spotty for years.

It was particularly critical of former secretary of state Colin Powell — who has acknowledged publicly that he used a personal email account to conduct business — concluding that he too failed to follow department policy designed to comply with public-record laws.