*. Easily search and filter messages.
*. High secure tunneling (GPG, SSL, anti-phishing).
*. Supports a lot of other e-mail client messages export/import.
*. Support and X-Face to Face.
*. Fully featured tool-bar.
*. Highly stable and loads pretty fast.
So, if you use Ubuntu you can install Claws Mail 3.7.9 by entering the below command.
sudo apt-add-repository ppa:claws-mail/ppaThat's it.
sudo apt-get update
sudo apt-get install claws-mail claws-mail-extra-plugins