It is about always a safety concern for Gmail. Using Autolog out you can feel more secure if any time you forget to sign out , don't worry Gmail auto logout will help you to sign out.
How to Auto logout From Gmail?I am going to show you how to Use auto logout feature in Gmail with mozilla firefox browser, other browsers would be same way to enable it, First of all install greasemonky script to your firefox browser. How to auto logout from gmail https://addons.mozilla.org/en-us/firefox/addon/greasemonkey.
On this page just clcik on the Green Install button and you are done.
Now you can customize your browser tabs and check the Gmail inbox for a test whether it shows any pop up message for Gmail Auto logout? If you have found that after 5 minutes never showing any auto logout message then may be you never setup the Auto logout Script properly. So you have to try again . Just refresh your browser and hit Ctrl+R for refresh. You can cancel autologout too by pressing Ctrl+R in every 5 minutes before.
Question:What if you have used this script in your FireFox browser for gmail?
Ans: You will get 5 minutes time to stay in your Gmail as log in and every 5 minutes later a pop up message will show up for saving your unsaved work. If you don't finish your work just cancel this button and you can still use Gmail for another 5 minutes.
Question:What if i auto sign out and can i get back my unsaved work?
Ans: Yes you will get your unsaved work as draft. Before sign out Gmail will automatically saved your writings as draft.
Question: Is it possible for me to increase the log in Time?
Answer: No. But if you want i can ask you to read this article for reedit one of the script which is responsible for Auto Gmail logout.