MailTracker!

MailTrack.io is an email tracking app for Gmail that lets you know if the emails you’ve sent have been read or not. Mailtrack extension adds the double check marks to your Gmail.

Track email opens for free without any 'Sent with' branding.See who opens your emails, when and where. Extension for Chrome, Opera.

SalesHandy is sales engagement platform. It provides email tracking, mail merge, document tracking & email scheduling. It allows user to send mass personalized email using mail merge, from gmail or their own SMTP servers.