[orbitbot]

I had the questionable pleasure of developing our first HTML emails at work this week, and found the following links helpful. I ended up working from the reference provided in the first (A list apart article) link post https://github.com/alistapart/salted .

http://alistapart.com/article/can-email-be-responsive

Which CSS is supported: https://www.campaignmonitor.com/css/

How to serve images: https://sendgrid.com/blog/embedding-images-emails-facts/

General guides and some templates:

https://www.campaignmonitor.com/guides/coding/guidelines/

http://templates.mailchimp.com/