Saleshandy is a cold email platform that helps organizations increase their email outreach operations without sacrificing quality. On Saleshandy, you can send hundreds (or thousands) of campaigns with multi-stage automated follow-up emails to your leads at once. You can use merge tags to customize your email campaigns and have automated follow-ups delivered based on the previous email's interaction (opens or clicks).
SendRecurring - SendRecurring allows you to setup, send, and maintain scheduled email reminders.
Gmelius - Gmelius is the first collaboration platform designed for G Suite and your company's daily tools.
Recurrr - Send recurring emails
Mailtrack.io - The best email tracking solution I've found. Free
FollowUpThen - The simplest way to schedule an email reminder
Yesware - Sell smarter with email tracking and more