If you did not add a “recovery email” on your Gmail account you are not going to be notified when someone has logged-in your account from a new device.
Recovery email is important because once your account is logged-in from a new device you will be notified through that email and gives you the option to stop your account from being compromised.
If ever there is no recovery email added to your Gmail account there’s a way on how you can check if your email has been logged-in from a new device or different device.
But before we get into that I would like you to know that you can prevent hackers from breaching your Gmail account by enabling 2-Step Verification on your Gmail account.
What is 2-Step Verification
Multi-factor authentication, multi-factor verification, 2-step verification, or 2-Factor authentication (2FA) gives you additional security for your account in addition to your password.
How Does it Work
It works as a second layer of security for your account commonly by using your mobile phone, app installed on your phone (Google Authenticator), or SMS sent to your mobile phone.
If you are going to login your account on a new device using your password you will be asked for security code from your mobile phone, an app (Google Authenticator), or SMS.
How Does it Work with Gmail
The most common way to do it is to download Google Authenticator on your mobile phone. Google Authenticator is available on both Android and iOS.
How to Check if your Account has been Logged-in from a New Device
Click you account’s avatar at the upper right corner of your screen then choose “Google Account”