WASHINGTON — The State Department is reviewing whether Hillary Rodham Clinton’s use of private email during her four years leading the agency violated policies designed to protect sensitive information, a senior department official said Thursday night.
The official said that Clinton’s use of personal email did not automatically break the rules but that the agency is looking into whether work emails sent from her personal account included sensitive information that must be handled on a system that meets specific security protocols.
The official did not elaborate on the security requirements.
The official, requesting anonymity to discuss sensitive internal deliberations, said the department would not know whether Clinton followed the rules until officials review the portion of emails that she turned over to the department last year as part of an agency effort to retrieve public records.
The official’s comments are the first time the agency has indicated any uncertainty on whether Clinton violated its email policies.
The review will determine whether Clinton’s correspondence in fact included sensitive information and, if so, whether proper security protocols were in place, as required by department policy.
‘‘We are not going to prejudge the outcome of the review of Secretary Clinton’s 55,000 pages of emails,’’ the official said.
Clinton’s unusual email practices have led to a storm of criticism this week from government-transparency advocates and Republican lawmakers, who say she has used the system to assert control over decisions regarding emails that would be released under federal public records law.
The controversy has created a new political complication for Clinton, the presumptive Democratic front-runner for president, with some Democrats expressing concern that her penchant for secrecy could become a weakness in the general election next year.
Clinton submitted the 55,000 pages of emails last year to the State Department after agency officials ask her to turn over public records in her possession.
State Department officials have said that Clinton and her private staff, not the agency, decided which of her email correspondence from her four years in office to turn over.
The agency under Clinton’s tenure did enforce restrictions on the use of private email.
A 2012 report by the State Department’s inspector general said an ambassador’s use of private email for public work was a violation of agency rules and created security risks. It was one of a string of criticisms that led to the forced resignation of the ambassador, Scott Gration, who had been posted in Kenya.
The report said that agency policies permitted the use of private emails only for ‘‘maintaining communication during emergencies.’’
Department policy requires that ‘‘normal day-to-day operations be conducted on an authorized information system, which has the proper level of security controls.’’
An unauthorized system, the report said, increases the risk of ‘‘data loss, phishing, and spoofing of email accounts.’’ In addition, the report warned that private email use could result in the ‘‘loss of official public records’’ because many systems do not have ‘‘approved record preservation or backup functions.’’
State Department officials have not answered questions about whether Clinton received a legal opinion from the agency before using her private email system, which was created as she took office in 2009. They have not said how the system worked, who installed it, or what steps were taken to ensure security and proper backup.
Clinton took to Twitter late Wednesday to call on the State Department to promptly release the records, saying: ‘‘I want the public to see my email.’’
On Thursday, her successor, Secretary of State John Kerry, promised that officials would review and publicly release the emails that had been provided by Clinton.
Kerry told reporters during a visit to Saudi Arabia that agency officials would ‘‘undertake this task as rapidly as possible.’’ But a State Department spokeswoman acknowledged the process would be time-consuming, given the volume of the record.
The pledge did little to satisfy Clinton’s political opponents or advocates for open access to government.
Federal records laws generally require agencies to release emails, exempting only those that fall in certain categories of sensitive, classified or personal information.
Moreover, Clinton did not address how she would handle records she did not submit to the State Department.
A Clinton aide would not say Thursday how many emails were withheld or describe the process used to decide which were purely personal.
Of the emails that were turned over to State, the Clinton aide said, 90 percent were correspondence between Clinton and agency employees using their regular government email accounts, which end in state.gov.
The remaining 10 percent were communications between Clinton and other government officials, including some at the White House, along with an unknown number of people ‘‘not on a government server,’’ the aide said. The aide requested anonymity because the emails are not yet public.
Washington Post staff writer Alice Crites contributed to this report.