wget ftp://ftp.mozilla.org/pub/mozilla.org/thunderbird/releases/12.0.1/source/thunderbird-12.0.1.source.tar.bz2
Install dependencies
sudo apt-get install libdbus-glib-1-dev gir1.2-notify-0.7 libnotify-dev yasm checkinstall libzip-dev zip
Remove the previous version and make sure that there's no existing comm-release directory
rm comm-release/ -rf
tar -xvf thunderbird-12.0.1.source.tar.bz2
cd comm-release/
./configure --disable-necko-wifi
The next step will take a little while (30-60 minutes on a slow computer)
make
And then install
sudo make install
Then install add-ons:
Lightning 1.4 (Sunbird is being discontinued)
Provider for Google Calendar 0.9 (otherwise you won't be able to dismiss calendar reminders)
Engimail 1.4.1 (see http://verahill.blogspot.com.au/2012/05/encrypting-your-email-chat-and-phone-in.html)
