You have to pay for basic features. Get MailTracker instead.
Attaches a visible image that says something like "sent with iTrackmail" in tracked e-mails. If you want to remove this annoying image, you have to pay. For me, the ability to send tracked e-mails without the image is a basic feature. Yesware (desktop service) does this for free, as well as MailTracker (iOS).