Скрипт на Python (ошибка)

##################################
#    Author: Alexander Perechnev #
#    (herfleisch@gmail.com)      #
##################################

#!/usr/bin/python

import os
import re
import smtplib
from email.MIMEText import MIMEText
import time
import urllib

############################
# Fill the next parameters #
############################
# SMTP server
smtp_server = "smtp.mail.ru"
# SMTP port
smtp_port = 25
# SMTP login
smtp_address = "mail@mail.ru"
# SMTP password
smtp_password = "passw0rd"
# Email topic
email_topic = "Topic"
# Mail body
mail_body = "Spam message."
############################

usedEmails = []
num = 0

while True:
    u = urllib.urlopen("http://otvet.mail.ru/")
    page = u.read()

    emailPattern = r"[0-9a-zA-Z_\-\.]+@[0-9a-z-A-Z\.]+\.[a-zA-Z]+"
    patternRe = re.compile(emailPattern)

    for address in patternRe.findall(page):
        if not address in usedEmails:
            num = num + 1
            msg = MIMEText(mail_body + address, "", "utf-8")
            msg['From'] = smtp_address
            msg['To'] = address
            msg['Subject'] = email_topic
            mailServer = smtplib.SMTP(smtp_server, smtp_port)
            mailServer.login(smtp_address, smtp_password)
            mailServer.sendmail(smtp_address, address, msg.as_string())
            mailServer.close()
            print(num, address)
            usedEmails.append(address)
            time.sleep(15)