Balsa
Balsa is a small and light email client written the GNOME project. As such it has tight integration with Gnome, however works quite well with other desktops or window managers.
Installation
Install the balsa package, available from the Official repositories.
Configuration
Balsa launches with the normal email client setup wizard that takes you through most setup. In addition there is a preferences item on the edit menu. Configuration files can be found in ~/.balsa.
One issue to which I found no good solution (unless you are running GNOME) is configuring the browser to open automatically when you click on a link in an email.
1) click on a link in an email and note which browser it is trying to load - in my case /usr/lib/firefox/firefox.
2) Check how much of that path exists and create what is missing. I had to create /usr/lib/firefox
mkdir /usr/lib/firefox
3) Make a soft link to your preferred browser.
ln -s /usr/bin/chromium /usr/lib/firefox/firefox