A White House review of her correspondence found that in 2017, she regularly discussed government affairs using a private email account with the domain "ijkfamily.com," which she shares with her husband Jared Kushner.
People "with knowledge of her reaction" told the Post that she didn't know the details of the rules.
The watchdog group, American Oversight, wrote a letter on Tuesday to members of the House Oversight Committee and the Senate Judiciary Committee. "The parallels between Ms. Trump's conduct and that of Secretary Clinton are inescapable," executive director Austin Evers wrote. "In both her use of personal email and post-discovery preservation efforts, Ms. Trump appears to have done exactly what Secretary Clinton did — conduct over which President Trump and many members of Congress regularly lambasted Secretary Clinton and which, they asserted, demonstrated her unfitness for office."
Peter Mirijanian, a spokesperson for Ivanka's attorney Abbe Lowell, said in a statement that she occasionally used her personal email before she was briefed on the rules, but never to convey classified information.
"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," he said, adding that she turned over her government-related emails to be permanently stored with other White House records.
But the review showed that Ivanka used her personal account to discuss government policies, her official work schedule, and travel details, which could be in violation of the Presidential Records Act.
If all of this sounds familiar, it's because, as Evers pointed out, it is. Ivanka's father called for Hillary Clinton to be imprisoned for her own email conduct, leading chants of "Lock her up!" at his rallies. Mirijanian said in his statement that Ivanka's use of a private server is different: "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."
Still, Evers said, "the extensive use of personal email by a senior public official raises important questions that merit investigation."
We reached out to Ivanka Trump's attorney Abbe Lowell and will update this story when we hear back.