GMass - GMass allows you to easily schedule emails, send out mass emails and mail merge campaigns and more with Gmail! Click here to learn about more features!
MailPoet - MailPoet is an email newsletter plugin for Wordpress.
Elevatr Email Marketing Automation - Fast and easy email marketing software
MailChimp - MailChimp is the best way to design, send, and share email newsletters.
Google Sheets Email Marketing - Email automation and validations directly from Google Sheets
Email Marketing: A Beginner's Guide - Master email marketing with these 3 short ebooks from Drip.