Gmail Mail Merge - Send personalized emails with attachments
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
Dynamic Campaigns by Sigstr - Share the most relevant content in every email
TL;DR Email - Send short emails & read emails as fast as you read Facebook
Dynamically Personalized Emails by QGraph - Hyper-personalized emails for E-commerce
mlist - Email newsletters, outside of the inbox