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).
SndLatr - SndLatr is a Gmail plugin that makes it easy to schedule emails to be sent automatically at a later time.
Gmelius - Gmelius is the first collaboration platform designed for G Suite and your company's daily tools.
WhatCounts - WhatCounts is a marketing channel that delivers smart, personalized messages to their target audiences.
Mailtrack.io - The best email tracking solution I've found. Free
SendLater - Email scheduler for Mac Mail.
Yesware - Sell smarter with email tracking and more