Lets get started... Installing Kivy through terminal pip insall kivy / pip3 install kivy Installing FPDF throught terminal pip install fpdf / pip3 install fpdf First there will be login with Google account window.Fill the correct credentials and click on SUBMIT if the credentials are wrong the error window will appear.click on retry to give correct credentials. now after in new window fill all the details and click on SUBMIT.If you want to clear all fields click on CLEAR Make sure that PC is connected to internet.After successfully sending message the sent window will appear. Check Your sent folder in G-Mail to confirm.