forge e-mails!
A little background information: Back before the days of popular email websites such as Hotmail, Yahoo, and G-mail that gives users a GUI, there was a system called SMTP (Simple Mail Transfer Protocol) that was the primary way to send messages.
We use python in orderr to send a mail from ANY mail address via Telnet, connecting with an SMTP server who don't requires autentication.
INSTALLATION
First you need to install DNSpython from https://github.com/rthalley/dnspython
After downloading build and install dnspython, type
python setup.py install