I'm using Icedove 2.0 for a while now [the Debian GNU/Linux version of Mozilla Thunderbird], and as I'm using the excellent Tango icons for everything on my system, I also had a Tango theme for my mail program. However, it was a tad buggy, so I went out looking for another one. I found DancingMouse for Thunderbird in the Mozilla sandbox [meaning it wasn't screened yet]. I downloaded it with my Mozilla account and installed, finding now all icons where were I'd expect them; the column with email subjects only showed icons when you had replied or forwarded, and the junk status column showed a mail icon for non-junk mails, cluttering up the space [I want it only show junk-icons for junk mails, nothing otherwise]. So I hacked the theme up a bit and now it looks like this:

You can download my modified version here. Enjoy :)