Gmail always keeps a log of your activity. So if you are suspecting somebody of hacking into or logging into your account without your knowledge, you can keep track of this through the ‘Last Account Activity’ feature. You will find this feature at the bottom of Gmail page, in the footer region. By clicking on details option present at the end of the ‘Last Account Activity’ line you can check the exact date, time, IP and type of access (browser, mobile, POP3) etc. used to log in into your account.
|Gmail multiple login information|