Komiko - Komiko is a sales intelligence solution to drive sales, retention and expansion.

ReadNotify - ReadNotify enables the user to know when email is sent and the reciever reads the email.

Mailtrack.io - The best email tracking solution I've found. Free

Bananatag - Find out what happens to your emails after you press send! Add email tracking, attachment tracking, email scheduling and templates to your daily emails.

EmailGreen - EmailGreen is a web-based email marketing and comprehensive CRM solution that is created to help organizations and companies manage their contacts and execute all the valuable campaigns as well as optimize social media channels among other so they c…

Intelliverse Email Tracker - Intelliverse Email Tracker provides insights to increase the ​productivity of your emails.