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).
Hiver - Manage Customer Support, Sales and Projects right from your Gmail inbox. Collaborate with Shared Labels, Shared Contacts, email notes, email reminders and email templates
Gmelius - Gmelius is the first collaboration platform designed for G Suite and your company's daily tools.
Clean Email - Clean Email is an online service that empowers you to take control of your mailbox.
Mailtrack.io - The best email tracking solution I've found. Free
MailClark - The Slack bot for external communications
Yesware - Sell smarter with email tracking and more