The Mozilla visual identity team, which I'm lucky enough to play a small role in, has just released the new Thunderbird logo! Jon Hicks was the illustrator behind both this new logo and the Firefox logo released a few months ago.
I've been using Thunderbird as my primary mail client for the past few months and have been generally pleased overall (particularly in comparison to Outlook, which I was using previously). It's exciting to see the progress of the project as it continually improves over time.
Check out Jon's explanation of the design process.
The new Thunderbird logo.

Comments
Paul Mayne - April 20, 2004 6:41 pm
Beautiful Logo. I too have been enjoying Thunderbird for over a month now and I absolutly LOVE it. Plugins are amazing. I just can't wait for better spam control.
Melanie - April 23, 2004 7:43 pm
Very sassy. I'm using the browser client and it looks like it is time to upgrade.
Adam Michel - April 27, 2004 2:06 am
When do we get us some ad buttons? We gotta get the word out!
Mark - July 12, 2004 1:32 pm
The new logo is fantastic when seen as on this page ... but when it is seen in its more common form , as an icon, it looks somewhat like an envelope wearing a cheap feather wig.
J - July 15, 2004 11:20 am
Mark describes the icon perfectly...but such a nice envellope with a rug. It doesn't look like anything else on the toolbar, so it does function ( that is, once I know what it is I can find it at a glance)...but sometimes I think just a capital "T" would be more recognizable...