An internal Education Department watchdog says Secretary Betsy DeVos has sometimes used personal email accounts for government business and did not always save the messages properly.

The agency's Office of Inspector General released a report Monday finding "limited" instances in which DeVos sent work emails from four personal accounts. Investigators say they found fewer than 100 emails to or from DeVos' personal accounts on the department's email system and found no evidence of "active or extensive" use of her personal accounts.

But they found that the emails, which should have been forwarded to her government account, "were not always being properly preserved." The report says many of the emails were from people congratulating DeVos on her 2017 confirmation or offering staffing recommendations.

House Democrats requested the review in October 2017.