That company is Platte River Networks (PRN), which managed her server from mid-2013 until early August 2015. The company is cooperating with the FBI.
That means that any emails Clinton deleted before she handed the server over to investigators may still be accessible. (Business Insider, 8/17/2015)
The mention of a backup copy of the server could be a reference to Datto, Inc., a company that made backups of Clinton’s server while it was in Platte River’s possession. (McClatchy Newspapers, 10/6/2015)