Spamming is a crime in many countries.
Use Yagmail and Keyring packages to send email securely in file
send_email_using_yagmail.py.
Send email using SMTP_SSL() in file
send_email_using_smtp_ssl.py.
Send email using .starttls() in file
send_email_using_starttls.py.
quickstart.py is a simple Python command-line application that makes requests to the Gmail API