Email Standards

Useful for identifying email display issues…
http://www.email-standards.org/

Email – build guide, info

http://www.webdesignerdepot.com/2009/11/a-guide-to-creating-email-newsletters/

Email Rules

http://net.tutsplus.com/misc/6-easy-ways-to-improve-your-html-emails/

Email/Newsletter Templates – rules…

Campaign Monitor:
CSS Guide:
http://www.campaignmonitor.com/css/
Rules:
http://www.campaignmonitor.com/blog/post/2533/a-guide-to-css-support-in-emai-2/
Images not displaying correctly in Hotmail + FF – ‘display:block’
http://www.viget.com/inspire/hotmail-image-problems-in-html-emails/