First lady Melania Trump often used private email accounts while in the White House, the Washington Post reported Tuesday night, citing her former adviser Stephanie Winston Wolkoff and messages that reporters viewed.

Why it matters: President Trump made the FBI investigation into 2016 Democratic presidential rival Hillary Clinton's private emails and server a major focus of his campaign and has continued to raise the issue during his re-election campaign.

• Richard Painter, chief White House ethics lawyer in the George W. Bush administration from 2005 to 2007, noted to WashPost that while a first lady isn't on the government's staff, "if she is doing United States government business, she should be using the White House email."

The allegations: Winston Wolkoff told WashPost that Melania Trump used "a private Trump Organization email account, an email from a MelaniaTrump.com domain, iMessage and the encrypted messaging app, Signal" and that the pair exchanged messages "multiple times a day."

• WashPost reports it "viewed messages dated after the inauguration that appear to be from private email and messaging accounts used by Melania Trump" on government hires and contracts, plans for overseas trip, the first lady’s Be Best initiative, the Easter egg roll, "and finances for the presidential inauguration, key parts of which Winston Wolkoff, an experienced New York City events producer, planned."

Of note: The email allegations do not feature in Winston Wolkoff's book "Melania and Me: The Rise and Fall of My Friendship with the First Lady," which was published on Tuesday.

• The Presidential Records Act allows for the use of personal accounts, but if records aren't "carefully maintained, the White House might not be able to produce them in response to a subpoena," WashPost notes.
• House Democrats launched an investigation last year into official communications records sent via "non-official electronic messaging accounts by non-career officials at the White House," including Jared Kushner, Ivanka Trump and former chief strategist Steve Bannon.
• Secretary of Commerce Wilbur Ross has also faced scrutiny over the use of private email to conduct official business.

What else she's saying: Appearing on MSNBC Tuesday night, Winston Wolkoff defended privately recording conversations she had with the first lady.

• "If she was my friend, it would be horrible," she said. But Melania and the White House had accused me of criminal activity and publicly shamed and fired me and made me their scapegoat Wolkoff said.
• "At that moment in time, that’s when I pressed record. She was no longer my friend and she was willing to let them take me down."

The other side: Axios has contacted the White House and Stephanie Grisham, Melania Trump's chief of staff and spokeswoman, for comment on the WashPost report.

• Grisham has previously said in a statement to news outlets that Winston Wolkoff's book was full of "mistruths" and "revenge" tactics. "Anybody who secretly tapes their self-described best friend is, by definition, dishonest," she said, per ABC.