The contents of the email were confirmed to CNN by a source familiar with the matter.
The Washington Post first reported on the email.
Stern wrote in the email, "It is also our understanding that roughly two dozen boxes of original presidential records were kept in the Residence of the White House over the course of President Trump's last year in office and have not been transferred to NARA, despite a determination by Pat Cipollone in the final days of the administration that they need to be. I had also raised this concern with Scott in the final weeks."
"Scott" refers to Scott Gast, another Trump attorney who was copied on the message.
Cipollone, along with his former deputy Patrick Philbin, were designated by Trump shortly before he left office to deal with the issues related to his presidential records.
CNN has not been able to reach Cipollone for comment on the email.