Thunderbird is a free email application that’s easy to set up and customize – and it’s loaded with great features!
To install Mozilla Thunderbird open a terminal window (press the SuperKey and type: terminal) and copy+paste the following lines:
sudo add-apt-repository ppa:mozillateam/thunderbird-stable
sudo apt-get update
sudo apt-get install thunderbird
To start Thunderbird press the SuperKey and type: thunderbird
Mozilla Thunderbird Homepage