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.
We’ve put together this guide to save you the time and frustration of figuring it out for yourself. With 23 different email clients tested, we cover all the popular applications across desktop, web and mobile email.
Looks like Campaign Monitor have updated their CSS support guide. Very useful it is too.