Spark Mail - Spark helps you take your inbox under control. Instantly see what’s important and quickly clean up the rest. Spark for Teams allows you to create, discuss, and share email with your colleagues

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

GoodByEmail - Declutter your inbox without giving third-party access to your emails! Reclaim GBs of storage, unsubscribe from pesky emails—all while keeping your emails off our servers. Experience full privacy with GoodByEmail, even offline!

Clean Email - Clean Email is an online service that empowers you to take control of your mailbox.

The Email Game - Get to inbox zero with game mechanics

MailClark - The Slack bot for external communications