I was reading this very insightful article by Linda Bustos of Get Elastic, the Ecommerce Blog. As a sender, I had to agree with her, when she made the point, that a subscriber list usually has more than a handful of GMail accounts on it, and most email recipients and some email marketers, don’t fully understand that GMail disables images in HTML emails by default, even when your customers have added you to his or her safe list.

So I’d like to share these eight tips for optimizing emails at GMail, when images are turned off:

1. Provide a link to a web-based version of your email near the top of your message.

2. Make sure your link works and your web-version displays properly.

3. Use alternate text for important images.

4. Include specific product names and prices where appropriate.

5. Avoid colors that will camouflage hyperlinks.

6. Place your best offers above the fold. As website visitors scan content looking for “trigger” keywords, so do email recipients. Often large images push the offers and calls to action down.

7. Test designs in different browsers. Many web browser will render differently due to coding. You may see images, or HTML text, in one type of browser, but not another. It is always good to verify.

8. Send out test emails to test accounts from a number of different email services before you blast to your entire list.

For more detailed information, you can read Linda’s article:

http://www.getelastic.com/email-design-for-gmail