:: download thunderbird 3.1.10 email client

# wget //mozilla.cdn.leaseweb.com/thunderbird/releases/3.1.10/linux-i686/en-US/thunderbird-3.1.10.tar.bz2

or you can download on thunderbird download page

:: installing thunderbird from source on linux

# tar -xjf thunderbird-3.1.10.tar.bz2 -C /usr/local/

:: open / running thunderbird 3.1.10

$ /usr/local/thunderbird/thunderbird

:: add thunderbird shortcut on gnome-panel

0. right-click gnome panel and select Add to Panel..
1. select Custom Application Launcher..
2. add value on Add Louncher, like:
Type: Aplication
Name: thunderbird
Command: /usr/local/thunderbird/thunderbird
3. click OK button

:: links
+ google
+ thunderbird