From the report itself:
The RNC has preserved 140,216 e-mails sent or received by Karl Rove. Over half of these e-mails (75,374) were sent to or received from individuals using official “.gov” e-mail accounts. Other heavy users of RNC e-mail accounts include former White House Director of Political Affairs Sara Taylor (66,018 e-mails) and Deputy Director of Political Affairs Scott Jennings (35,198 e-mails). These e-mail accounts were used by White House officials for official purposes, such as communicating with federal agencies about federal appointments and policies.