Gmail can now notify you when a recipient reads email sent by you. You can also know when and how many times your email was opened, even from where and who with the Chrome extension Streak Email Tracking. This is very useful in day-to-day use not only for business correspondence but also for personal use to ensure the proper person receives and reads the information that was sent.
Streak’s email tracking plugin for Chrome and Safari notified you when one of your recipients reads your Gmail message. You can also get to know the exact time and how many times the email was opened, which device used to read the email, and even the recipient’s location.
Once installed, enable ‘Tracks emails by default’ option. Now, each time you send an email, Streak will automatically track it. You can easily enable/disable this option at any time depending on your situation.
When an email is read, a popup notification appears right top of your Gmail sent mailbox and an eye icon next to your tracked email turns green. Just hovering over the eye icon to know how many times, the email has been read. To know the time and location of recipient just click the icon.
Please note that Streak isn’t a free service. It tracks 200 emails a month for free before charging a premium for extra emails. You can get more details from here.(source)
