Official State Department police — as implemented in 2009, states that all personnel — including officials — must use emails provided on the official server. Clinton, who was appointed Secretary of State in 2008, continued to always use her private email.
However, Republicans and transparency advocates expressed doubt that she likely turned over everything related to her official capacity. Many Republican legislators have shown a particular interest in emails relating to the Benghazi incident in which a US ambassador was killed in Libya which, they say, Clinton would have an interest in hiding.
Current Secretary of State John Kerry has said that it will take months to fully review the situation which means that the issue is likely to come up again after Clinton has officially announced her run for the 2016 Democratic presidential nomination.
Clinton had said that she did not want to carry two devices, citing the inconvenience. However, it was later revealed that she admitted to carrying two devices previously, anyway.