Faced those times when you sent an important email to someone and later they told you that the email wasnt received ? This service can help you.
The service is free and very simple to use. Just enter your email address and the subject of the email you wish to send. Then choose a tracking image and the number of times you wish to be notified about the recipient opening your email. On activation, it should show you an image, right click the image and paste it into the email you wish to send.