Simple Mail Transfer Protocol (SMTP) is a standard for e-mail transmission across networks. E-mail servers and other mail transfer agents use SMTP to send and receive e-mail messages. E-mail client applications regularly use SMTP only for sending e-mails. To perform brute-force password auditing against SMTP, we can use the smtplib module, which helps us to connect to SMTP.

As usual, import the required modules:

import sys, smtplib, socket 
from smtplib import SMTP 

Set the IP and USER. You can also get these values as input parameters:

IP = "127.0.0.1" 
USER = "admin"  

Check the SMTP with each and every password in the password list:

attackNumber = 1 
with open('passwordlist.txt') as f: 
    for PASSWORD in f: 
         try: 
               print "-"*12 
               print "User:",USER,"Password:",PASSWORD 
               smtp = smtplib.SMTP(IP) 
               smtp.login(user, value) 
               print "\t...