From the story here:
WASHINGTON (AP) -- Former Secretary Hillary Clinton failed to turn over a copy of a key message involving problems caused by her use of a private homebrew email server, the State Department confirmed Thursday. The disclosure makes it unclear what other work-related emails may have been deleted by the presumptive Democratic presidential nominee. ...
Judicial Watch president Tom Fitton said the November 2010 email cited in the inspector general audit was one of several work-related emails that his group identified that Clinton sent or received but later failed to turn over the State Department.
"Contrary to her statement under oath suggesting otherwise, Mrs. Clinton did not return all her government emails to the State Department," Fitton said. "Our goal is to find out what other emails Mrs. Clinton and the State Department are hiding."