Use Conky Manager
How to install
Flexible, just edit at two places to strect it for your screen
Two colors scheme, easily changed through the settings file
Mail from gmail, setup inside the settings file
Dwnload the archive. Extract the archive, there are two thing inside that Octupi.cmtp.7z and .fonts. Drad ang drop the first into Conky Manager and copy the second in you home directory.
Open the file ~/.conky/Octupi/co_main and change the value of minimum_size according to your screen size.
Open the file ~/.conky/Octupi/settings and change the values (self-explanatory)
Install font type fc-cache -v
Install vnstat for network statistics, type
sudo apt-get install vnstat