“It is described as a large bird, capable of creating storms and thundering while it flies. Clouds are pulled together by its wingbeats, the sound of thunder made by its wings clapping, sheet lightning the light flashing from its eyes when it blinks, and individual lightning bolts made by the glowing snakes that it carries around with it. In masks, it is depicted as many-colored, with two curling horns, and, often, teeth within its beak.”

Read the page you’re linking before telling someone the Thunderbird hs nothing to do with thunder.

>make [envelope] more retangular

Initially I was thinking that the lack of parallel lines on the envelope looked odd, but now looking at it in isolation I’m thinking that the particular angle on the envelope, which is slighted rotated, actually really helps to make the icon three dimensional. Since this is an overall goal, I would keep the angle of the envelope the same, or even actually increase the skew slightly, so it is even less rectangular.

>crisper [envelope] with a white color

I would explain the rationale here a little bit, idea being that paper will yellow and darken as it ages. So switching the paper from a tan/yellow shade to a crisper and brighter shade of white will help to make the icon feel new and fresh.

>make the icon feel more like a complete circle
>make [wings] more of a circle

Instead of circle I would say sphere. This follows with the changes to the new Firefox icon, and although there isn’t a literal sphere for the wings to wrap around (just a rotated envelope), I think James in comment #3 describes the feel well saying the more spherical wings would convey a “protective shield around your mail.”

Sean Martell’s draft update of the Mozilla Lab’s Snowl icon shows a similar wings + sphere approach, although in this case there is an actual sphere for the wings to cradle: http://mozilla.seanmartell.com/snowl_2.png

The feathers in the Firefox tail adapt very well as actual feathers :)

I looked in Wikipedia, but found nothing except Jurassic birds, who don’t even fly (like present day ostriches).

Now one more “pretty please”: PLEASE MAKE A DOCUMENT ICON FOR THUNDERBIRD (for *.EML files). It lacks it! Simple envelope picture will do perfectly. Maybe with smaller Thunderbird icon on it, just how it is done in Firefox document icon.

P.S. I found a funny misspelling in your Creative Brief PNG image – “Thunderbirdbird” (should be just “Thunderbird”) :)

The actual logo of Firefox has a front perspective, the actual logo of Thunderbird has “side”-perspective. I love the perspective but is not coherent. if there is a subtle change of perspective will be slightly larger head size of the bird?

The logo of Firefox is very flat, the logo of Thunderbird is more 3D.

The logo of Firefox has fire, the logo of Thunderbird has no metaphor alluding to the storm.

The envelope of the mail is very big and it’s difficult to perceive it as such.

There should be lightning somewhere, even few.

@Dave, yes!! it’s good idea:

Thunder – Bird

In the actual logo don´t appear nothing related whith a… ¿storm? ¿wind? ¿wrap? ¿thunder? ¿bolt? ¿ligthning? ¿more shinny? I don´t know… ¿Sugestions?

¿What is Thunder – Bird? ¿What evoques in the mind?

I do hope that the bottom dual shadows are worked on. I’ve never liked the blurred one mostly because it just doesn’t make any sense.

I understand that things are already rolling but perhaps to help achieve a more well rounded result, the envelope could be lowered to the bottom and rounded.
The logo itself is rounded, but not round.
Curling the wings inwards would also help to round it off.

Check out what I mean about rounding the bottom. I rounded the whole logo somewhat, but not by curling in the wings.
http://www.accessfirefox.org/Something_Like_This.php

“…it’s because I think we should be viewing the icon as an exterior chassis for an underlying engine that has recently undergone some really significant changes.”

So are any such changes planned for Thunderbird too? Thunderbird development has been pretty slow for a while and some major improvements are definitely welcome!

Hugging a globe is different from hugging an envelope though, having the bird too round and wrapping too much like the fox might look wierd because of those differing shapes they’re hugging.
Of course, it might look really good, and more like a protective shield around your mail.