GMass - GMass allows you to easily schedule emails, send out mass emails and mail merge campaigns and more with Gmail! Click here to learn about more features!
Spark Mail - Spark helps you take your inbox under control. Instantly see what’s important and quickly clean up the rest. Spark for Teams allows you to create, discuss, and share email with your colleagues
Email Testing By Inbox Pirates - Preview, Analyze & Test emails with one click.
Hunter - Find all the email addresses related to a domain
Interseller - Interseller helps find contact information, reach out to them with email automation and syncs it all into your database.
Email2Go.io - Perfect emails are born here