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

Intercom - Intercom is a customer relationship management and messaging tool for web businesses. Build relationships with users to create loyal customers.

mlist - Email newsletters, outside of the inbox

Drift - A messaging app that helps you grow your business.

TL;DR Email - Send short emails & read emails as fast as you read Facebook

Faqbot - Build your chatbot for FAQ, sales and lead generation automation.