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

OptinMonster - OptinMonster helps to convert abandoning website visitors into subscribers and customers.

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

Sleeknote - Set up lead capture forms on your website in minutes. No coding required. Sync your new email leads with your favorite email service provider. Try for free.

Nylas Mail - The Nylas Cloud API powers your application with email, calendar & contacts features. Built-in features for better email, calendar, and contact management.

Poptin - Create engaging and high converting website pop ups and contact forms in minutes. With Poptin, you get access to a feature-packed conversion rate optimization toolkit that converts more website visitors into email subscribers, leads, and customers.