Mailmeteor - Send hundreds of personalized emails with Gmail.
Kingmailer - Kingmailer helps you send, receive and route/forward emails.
Mailazy - Modern Email Delivery API
Flexmail Solution - Professional email marketing with powerful and easy-to-use features
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!
Dragon Responsive Email Designer - Dragon Email Designer provides an intuitive drag and drop newsletter design tool.