At least four top current and former White House officials occasionally used private email in their official capacity as White House officials, sources told CNN. The New York Times reported Monday
night that that "at least six" officials used private email to conduct White House business after Politico first reported that Jared Kushner
, the President's son-in-law and senior adviser, periodically used a private email account.
The use of private email was a defining issue of the 2016 presidential election, when then-candidate Trump frequently slammed his opponent Hillary Clinton's use of a private server during her time as secretary of state. Several of the emails Clinton sent or received were later determined to be classified by various government agencies
, though Clinton had said that none of the emails were marked classified at the time she sent them.
There was no indication that the White House officials who used personal email maintained their accounts on a private server or that they shared classified information.
Former White House chief of staff Reince Priebus, former chief strategist Steve Bannon and others occasionally used personal email during their time at the White House, two sources with knowledge of the emails told CNN.
Kushner's lawyer Abbe Lowell also confirmed to CNN on Sunday that Kushner
occasionally used a private email account for correspondence with fellow administration officials.
"Mr. Kushner uses his White House email address to conduct White House business," Lowell said in a statement. "Fewer than a hundred emails from January through August were either sent to or returned by Mr. Kushner to colleagues in the White House from his personal email account."
Lowell said that the emails on Kushner's private account were "usually forwarded news articles or political commentary and most often occurred when someone initiated the exchange by sending an email to his personal, rather than his White House, address."
White House officials are advised to use their official White House email addresses for official business and though it is not illegal to use personal email, federal law requires all White House records -- including emails -- be preserved.
"All White House personnel have been instructed to use official email to conduct all government related work," White House press secretary Sarah Sanders said in a statement. "They are further instructed that if they receive work-related communication on personal accounts, they should be forwarded to official email accounts."
While the White House has not issued any new warnings or guidance, one source said lawyers in the Office of the White House Counsel periodically remind White House staff to forward any personal emails to their official account to ensure they are recorded in accordance with the Presidential Records Act.
Kushner did just that, Lowell said, noting that "all non-personal emails were forwarded to his official address, and all have been preserved, in any event."
Ivanka Trump, an assistant to the President, also used her private email to correspond with administration officials about working on policy issues before she was officially named to a White House position in March.
According to The New York Times, Stephen Miller, a top adviser and presidential speechwriter, and National Economic Council director Gary Cohn also used private email accounts. CNN has not independently verified this reporting.
Documents obtained by watchdog group American Oversight via a Freedom of Information Act
request found two emails sent by Ivanka Trump's private email address to Small Business Administrator Linda McMahon on the topic of women's entrepreneurship.
The emails were sent February 28, nearly a month before Trump formally stepped into her White House role as assistant to the President. However, she referred to White House staffer Julie Radford as "my chief of staff" in one of the emails.