"It's just the height of hypocrisy," she said in an interview with SiriusXM's Zerlina Maxwell after being asked to respond to the news on Monday.
Clinton called her use of a private server "a dumb mistake but a dumber scandal" and said she regrets that the country "had to go through it."
During the campaign, Trump repeatedly called for an investigation of her use of the private server and said in a debate that Clinton would "be in jail" if he was in charge.
A White House official who spoke with ABC News did not dispute the Times' report that at least six administration officials occasionally used private email to communicate about official business since Trump took office.
While it is not illegal for White House staffers to use personal email accounts, they must forward all work-related communications to their official White House email accounts.
White House press secretary Sarah Sanders confirmed this for ABC News today.
"All White House personnel have been instructed to use official email to conduct all government-related work," she said. "They are further instructed that if they receive work-related communication on personal accounts, they should be forwarded to official email accounts."
ABC News' Alexander Mallin and Katherine Faulders contributed to this report.