If you open your gmail in multiple computers and if you forget to sign out. You can do it remotely!
How?
At the bottom of your inbox, you'll see information about the time of the last activity on your account and whether it's still open in another location
when you click on details a new window appears as
Now you can select sign out all other sessions to sign out !
Many might know this,the article is for those who don't know this feature!
Jul 12, 2009
Remote sign out in GMAIL
