8 sites to get free images for your next email design https://www.campaignmonitor.com/blog/email-marketing/2014/07/free-images-email-marketing-campaigns/
10 essential email design tips from Justine Jordan http://content.myemma.com/h/i/268624866-10-essential-email-design-tips-from-justine-jordan
Understanding Retina Images in HTML Email https://litmus.com/blog/understanding-retina-images-in-html-email
The 6 Best Practices for Responsive HTML Email Design https://mailbakery.com/blog/the-6-best-practices-for-responsive-html-email-design/
How to Use the Right Images in Your Email Design http://blogs.constantcontact.com/use-images-in-email-design/
Improve Email Marketing Using Principles of UX Design http://isenselabs.com/posts/how-to-improve-email-marketing-using-principles-of-ux-design
Email Development Best Practices https://www.emailonacid.com/blog/article/email-development/email-development-best-practices
5 Email Design Best Practices Every Marketer Should Know https://blog.aweber.com/email-marketing/the-5-email-design-best-practices-every-marketer-should-know.htm
Three steps to mastering the email GIF https://www.mailjet.com/blog/mastering-the-email-gif-frame-by-frame/
25 Wonderful Examples of Animated GIFs in Email Marketing Templates https://mailbakery.com/blog/25-wonderful-examples-of-animated-gifs-in-email-marketing-templates/
The anatomy of a high-converting email newsletter https://www.campaignmonitor.com/blog/post/4561/anatomy-of-email-newsletters
9 Tricks to Design The Perfect HTML Newsletter http://www.hongkiat.com/blog/design-perfect-newsletter/
6 Email Tips and Tricks That *Don’t* Actually Work https://blog.hubspot.com/marketing/email-tips-that-dont-actually-work
How to use Images in Email Marketing http://blog.astonishemail.com/blog/2014/12/1/how-to-use-images-in-email-marketing
Bulletproofing images in email design http://blog.jmwhite.co.uk/2014/10/13/bulletproofing-images-in-email-design/
