Using the Viagee repository.
Here is how to add gnome-gmail to apt repository resources for your system, letting you install and
automatically upgrade with standard tools.
First, add a reference to the viagee PPA to your /etc/apt/sources.list file (as root):
deb http://davesteele.github.io/viagee/repo viagee main
Add the repository key to your apt key ring:
# wget -q -O - https://davesteele.github.io/key-366150CE.pub.txt | sudo apt-key add -
Install the packages with :
$ sudo apt-get update
$ sudo apt-get install viagee
The package will be updated with every 'apt-get upgrade'.
Logout of your desktop session to complete the configuration for your account.