According to the report by the office of the State Department inspector general, Clinton disregarded various cybersecurity guidelines and incurred unnecessary risks while serving as the nation's top diplomat from 2009 to 2013.
The report, obtained by news outlets on Wednesday, was the culmination of an official inquiry which found "serious shortcomings" in how Clinton and her predecessors managed the security of their emails. Clinton's failures were singled out as more egregious than her predecessors' as the State Department had reportedly made increased efforts to communicate the need for cybersecurity measures.
The 78-page analysis reportedly cited "longstanding, systemic weaknesses" related to the agency's communications.
In particular, it noted that despite guidelines to the contrary, Clinton used mobile devices to conduct official business on her personal email account and private server and never sought approval from senior information officers.
The report also noted that Clinton and her senior aides had not cooperated with the investigation. Clinton spokesman Brian Fallon said the report showed no successful breach of the private server she used.
"The report shows that problems with the State Department's electronic recordkeeping systems were longstanding and that there was no precedent of someone in her position having a State Department email account until after the arrival of her successor," Fallon said in a statement.
The Associated Press news agency revealed in 2015 that the clintonemail.com server used by Clinton was in the basement of home while she was secretary of state.
Clinton apparently used the private server for work and personal emails, including some that have since been classified.
The presumed Democratic presidential nominee has been dogged for months by allegations she endangered national security. Added to other jibes by the likely Republican candidate, Donald Trump, Clinton's laxity in her email security will likely be used against her to bolster a narrative that she is not to be trusted.
Bolting the door after the horse has bolted
The State Department is "already working" to improve its email and records management system, one of its spokesmen, Mark Toner, said.
"It is clear that the department could have done a better job preserving emails and records of secretaries of state and their senior staff going back several administrations," Toner added.
The State Department acknowledged that compliance with its rules had been "inconsistent across several administrations." Toner added that the department had taken a number of steps by early 2015 to improve its cybersecurity.
Clinton plays down report findings
Clinton herself acknowledged in the campaign that her email setup was a mistake, but said she never sent or received anything marked classified at the time.
The FBI has also been probing whether Clinton's use of a private email server imperiled government secrets.
jbh/sms (AFP, AP)