Designing an HTML email that renders consistently across the major email clients can be very time consuming. Support for even simple CSS varies considerably between clients, and even different versions of the same client.

CSS Support in Email Clients from Campaign Monitor

As web designers, we’ve grown pretty good at understanding how to create a modern, semantic, accessible website using XHTML and CSS. We understand what makes a good website, and how to make it happen. When it comes time to design emails though, do all the same rules apply? Are there things we should be doing specifically for email that don’t make sense on a website? In this article we’ll discuss the technical, design and information elements that make up a successful HTML email.

2008 Email Design Guidelines from Campaign Monitor

Seasoned graphic designers wouldn't dream of sending a print project to press without first approving an accurate proof. Your client's email marketing campaign should be no different. You need to be sure you know what your design looks like on the different email clients your readers might be using.

Proof Your Email Designs in Different Email Clients from Creative Techs

Designing for an email is still quite far off from designing for a browser. In fact, email reader standards are pretty historic in the sense that (a) it requires designers to degrade their modern coding practices and (b) there really are no true standards.

Outlook 2007 and Gmail are the bane of my existence.

9 Best Practices for Email Design from Vdot Media

Mathew Patterson of Freshview has written a new article called The Principles of Beautiful HTML Email; it's for people that are new to HTML emails or people that have been ignoring the power of email marketing.

“The typical email client is quite similar to a web browser from 1999, with limited or inconsistent support for modern HTML and CSS. The best place to start is with the Campaign Monitor Guide to CSS Support in Email, which gives you an overview and helpful chart that shows what is and is not supported in the major email clients. You may find SitePoint's article on Writing HTML Email useful as well.”