HubSpot Free Email Marketing - Powerful drag and drop email marketing in the HubSpot CRM
Really Good Emails - A large collection of good product email design.
Email Marketing: A Beginner's Guide - Master email marketing with these 3 short ebooks from Drip.
Good Sales Emails - Best sales emails from great companies
Elevatr Email Marketing Automation - Fast and easy email marketing software
Great Email Copy - A dose of emails from around the web.