From the story here:
Judicial Watch says it obtained the documents after suing the State Department for its failure to respond to a Freedom of Information Act request filed in March 2015. The FOIA request sought “All emails of official State Department business received or sent by former Deputy Chief of Staff Huma Abedin from January 1, 2009 through February 1, 2013 using a non-state.gov email address.”
Judicial Watch notes that the 115 Clinton email exchanges were not among the 55,000 pages of emails that Clinton previously handed over to the State Department, contradicting her claim that she had turned over all of her government emails.