Thanks to an extension for Thunderbird called Display Contact Photo, you can now view Gravatars within emails in Thunderbird. The Gravatar blog has a good explanation on how to setup and install the extension. I’ve installed the extension as Thunderbird is my email client of choice. So don’t be surprised to see a beer mug accompanying replies from me although I’m not sure yet if both parties need to be running the extension to see the images.
Gravatar Support In Thunderbird Thanks To Extension