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
Mailook - Identify & fix your email deliverability issues for free 👀
Clean Email - Clean Email is an online service that empowers you to take control of your mailbox.
Mailivery - Reach the Inbox, not the spam folder.
MailClark - The Slack bot for external communications
Sidemail - The simplest way to send transactional emails. Sidemail makes sending transactional emails trivial, it's perfect for side projects, MVPs or the next big thing.