Of course, the whole thing gets even more difficult when there are email client developers, like Microsoft, actually reverting back to older HTML standards for newer email clients, like they did with Outlook 2007 which has less CSS support than the previous version of Outlook had.

But, it’s not a lost cause. There are definitely things that you can do to optimize your HTML so that it will render well in the majority of email clients.

1. Test your HTML using the w3c Markup Validation Service and fix any major coding errors (like no end tags, etc.)
2. Use an email testing service ($$) such as Litmus
3. Do your own testing. Create a test group using as many different email addresses (i.e. Yahoo, Gmail, Hotmail, domain, etc.) and test your messages against them.
4. Use pre-tested HTML email templates when possible.
5. Implement the 9 Best Practices for Email Design

One day, thanks to the hard work of the Email Standards Project, we will all celebrate the day when all email is rendered equally. Perhaps we’ll make it an international holiday for email marketers.

Until then, good luck.