Intercom - Intercom is a customer relationship management and messaging tool for web businesses. Build relationships with users to create loyal customers.
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
HelpDocs - Educate your users with a super simple knowledge base that’s built for teams just like yours.
mlist - Email newsletters, outside of the inbox
Support Hero - Educate your customers through self-help support
TL;DR Email - Send short emails & read emails as fast as you read Facebook