ReadNotify - ReadNotify enables the user to know when email is sent and the reciever reads the email.
Boomerang for Outlook - Boomerang for Outlook offers email productivity tools to track, schedule and send mails at the right time.
GetNotify - GetNotify is a free email tracking software solution.
Outlook4Gmail - Outlook4Gmail provides easy synchronization of your Outlook and Google accounts
WhoReadMe - WhoReadMe is an email tracking solution that provides details on read duration, recipient location, organization name, operating system etc.
Covideo - Covideo is a Video Email Platform for Businesses that enables companies to communicate quickly and effectively with their customers.