Integrate thunderbird into Gnome new indicator applet

In Ubuntu
Here is the link: http://ubuntuforums.org/showthread.php?t=1439519
The other: http://www.omgubuntu.co.uk/2010/05/how-to-add-thunderbird-to-messaging.html

Create a Desktop file for thunderbird in

/usr/share/applications/thunderbird.desktop

Edit

[Desktop Entry]
Name=Thunderbird Mail
GenericName=Mail Client
Comment=Manage your email and contacts
Exec=thunderbird %u
Icon=evolution
Terminal=false
Type=Application
Categories=Application;Network;Email;
StartupNotify=true

X-Ayatana-Desktop-Shortcuts=Compose;Contacts

Name[en_GB]=thunderbird.desktop

[Compose Shortcut Group]
Name=Compose New Message
Exec=thunderbird mailto:
OnlyShowIn=Messaging Menu

[Contacts Shortcut Group]
Name=Contacts
Exec=thunderbird -addressbook
OnlyShowIn=Messaging Menu

Add new file in

/usr/share/indicators/messages/applications/thunderbird

Edit

/usr/share/applications/thunderbird.desktop