MailTrack is a free Google Chrome extension that helps you know when your emails are read. You just need to click the button below and within seconds you will have the ✓✓ on your Gmail. A popup window will ask for your confirmation. Next, a new tab will be opened to connect MailTrack to your Google account. No room for misunderstandings here: the double-checks from MailTrack are actually for free, with no limits, really forever.