PUBLIC MARKS with tags it & html

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 CSS support in email clients guide to save you the time and trouble of figuring it out for yourself. With 21 different sets of results, all the major email systems are covered, both desktop applications and webmail. If you do notice results different to the ones we've listed, we'd love to hear your feedback. Email clients (particularly webmail) often change without notice, so we appreciate your help keeping this resource up to date.

View Selection Source — simple JavaScript bookmarklet (favelet) or an User JavaScript which allows you to see HTML source of any part of page, it's very useful for web developers. You probably know it from Firefox.