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.

Right Inbox - Schedule Emails in Gmail To Be Sent Later

GetNotify - GetNotify is a free email tracking software solution.

Recurrr - Send recurring emails

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

FollowUpThen - The simplest way to schedule an email reminder