Sanebox - SaneBox is a cloud-based service that allows users to filter and manage their emails.
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
HEY - Email at its best, new from Basecamp.
Clean Email - Clean Email is an online service that empowers you to take control of your mailbox.
MailClark - The Slack bot for external communications
Teknik Mail - Webmail service. Powered by RainLoop.