White House senior adviser and first daughter Ivanka Trump used a private email account with a domain that she and her husband Jared Kushner shared to communicate with White House aides, Cabinet officials, and others about official business, according to a report Monday.

Trump used the account to send hundreds of emails and often broke federal records rules for a significant portion of 2017, a White House review of her correspondence revealed, the Washington Post reports.

Trump and Kushner established personal emails in December 2016 with a domain of “ijkfamily.com” through a Microsoft system, which stores the emails. She used the account to share information on government policies and official business less than 100 times, usually in response to administration officials who contacted her first via the personal email address.

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She also sent hundreds of emails concerning her official work schedule and travel details to herself and personal assistants, potentially violating federal records rules.

The revelation caught some advisers to President Trump off guard, and were similarly surprised when Ivanka Trump said she was unaware of some of the specifics of the rules. After she informed White House lawyers of this issue, the White House found that Ivanka Trump had not been getting information from the White House about using private emails.

The White House referred questions about Ivanka Trump’s use of a private account and server to her attorney and ethics counsel, Abbe Lowell. Although President Trump has frequently railed against former Secretary of State Hillary Clinton for using an unauthorized email server, a spokesperson for Lowell argued the two situations were different.

“While transitioning into government, after she was given an official account but until the White House provided her the same guidance they had given others who started before she did, Ms. Trump sometimes used her personal account, almost always for logistics and scheduling concerning her family,” Peter Mirijanian said in a statement.

“Ms. Trump did not create a private server in her house or office, no classified information was ever included, the account was never transferred at Trump Organization, and no emails were ever deleted,” Mirijanian said.

White House ethics were informed about the emails as they were examining a tranche of emails compiled by several Cabinet agencies.

The Presidential Records Act demands that all official White House correspondence be kept for each administration, meaning that use of a personal email account for official business could violate the law and increases the potential of mishandling of information or hacking.