Finding the mail server from an email address

Websites often need to verify an email that is entered by a user for validity. We can verify an email in a few lines of code in Python. First step is to confirm that the email is of the accepted format, to ensure that no random input is accepted as an email. Next is to see whether the email address indeed exists. Due to restrictions in the major email service providers such as Gmail and Hotmail, this code may not work completely. Nevertheless, it gives an overall idea on a given email address.

Getting ready

To run this recipe, you first need to have a from email address that you will use to test the other email addresses (marked as toaddress).

How to do it...

Listing 5.8 shows us the code that finds the domain name from the given email address and verifies it:

#!/usr/bin/env python 
# Python Network Programming Cookbook, Second Edition -- Chapter - 5 
# This program is optimized for Python 2.7.12 and Python 3.5.2. 
# It may run on any other version...