You can disable it on the dashboard on the developer website. Note: Mailtrack adds a signature to all emails by default.
It is also possible that recipients notice that they are tracked by you which may impact your personal or business relationship. If you dislike that, it seems almost hypocritical to use such an extension. Tracking read emails is not that different from being tracked by companies on the Internet. Privacy comes to mind first and foremost. While MailTrack may look like a great idea to get read confirmations on Gmail, it is a problematic extension for several reasons. According to the company, it is never accessing email contents or keeping copy of emails on company servers.
