The latest version is 3.5.0
All in all, if you want to manage your messages in a simple yet powerful e-mail client, Sylpheed is one of the applications that you should try. It comes with a good response time, a user-friendly GUI and it did not hang or freeze in our tests. A portable counterpart is also available for those who want to use their e-mail on the fly
To install Sylpheed just run the following commands via your systems Terminal.
sudo add-apt-repository ppa:klaus-vormweg/sylpheed
sudo apt-get update
sudo apt-get install sylpheed
That's all enjoy!