"He stated that these efforts included (1) examining the servers and others devices to identify suspicious logins or other activity, and (2) searching numerous datasets to determine whether foreign adversaries or known hostile domestic actors had accessed emails that the [team] had confirmed to contain classified information."
Former FBI Director James Comey, in his July 5, 2016, press conference regarding possible cyber intrusion of Clintons email servers, said the FBI had not found direct evidence of any intrusion into her personal email domain, but didn't rule out the possibility.
"Given the nature of the system and of the actors potentially involved, we assess that we would be unlikely to see such direct evidence. We do assess that hostile actors gained access to the private commercial email accounts of people with whom Secretary Clinton was in regular contact from her personal account ... She also used her personal email extensively while outside the United States, including sending and receiving work-related emails in the territory of sophisticated adversaries. Given that combination of factors, we assess it is possible that hostile actors gained access to Secretary Clinton's personal email account."