How are you logging on. Is it on a browser and if so which one or are you using an email app?
Hi. I use Google. I am not very tech savvy. Si if I need to do anything different I will need detailed instructions.
When you say "Google" if you mean using the Chrome web browser, once you are logged onto your email account, to log out you can click on the three horizontal bars at the left hand side and a new side bar will open where you will see your user name with a circle icon to the left. Click on that icon and it will log you out of your account.
If you don't do that you will eventually be logged out when your session times out which I think is now about an hour or if your browser is fully closed.