Email Verification in Python 

	import re
	import smtplib
	import dns.resolver
	# Address used for SMTP MAIL FROM command
	fromAddress = 'corn@bt.com'
	# Simple Regex for syntax checking
	regex = '^[_a-z0-9-]+(\.[_a-z0-9-]+)*@[a-z0-9-]+(\.[a-z0-9-]+)*(\.[a-z]{2,})$'
	# Email address to verify
	inputAddress = input('Please enter the emailAddress to verify:')
	addressToVerify = str(inputAddress)
	# Syntax check
	match = re.match(regex, addressToVerify)
	if match == None:
	print('Bad Syntax')
	raise ValueError('Bad Syntax')
	# Get domain for DNS lookup
	splitAddress = addressToVerify.split('@')
	domain = str(splitAddress[1])
	print('Domain:', domain)
	# MX record lookup
	records = dns.resolver.query(domain, 'MX')
	mxRecord = records[0].exchange
	mxRecord = str(mxRecord)
	# SMTP lib setup (use debug level for full output)
	server = smtplib.SMTP()
	server.set_debuglevel(0)
	# SMTP Conversation
	server.connect(mxRecord)
	server.helo(server.local_hostname) ### server.local_hostname(Get local server hostname)
	server.mail(fromAddress)
	code, message = server.rcpt(str(addressToVerify))
	server.quit()
	#print(code)
	#print(message)
	# Assume SMTP response 250 is success
	if code == 250:
	print('Success')
	else:
	print('Bad')