simple threaded mail handler

error.log

Traceback (most recent call last):
  File "<console>", line 1, in <module>
  File "../apps/home/mailhandler.py", line 46, in handle
    if self.send(to=[user.email], subject=subjects[mtype], text_body=plaintext, html_body=htmly):
  File "../apps/home/mailhandler.py", line 55, in send
    msg = EmailMultiAlternatives(subject, text_body, from_email, to)
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/threading.py", line 438, in __init__
    assert group is None, "group argument must be None for now"
AssertionError: group argument must be None for now

mail.py

class MailHandler:
    def getTemplates(self, location):
        try:
            plaintext = get_template(location + '.txt')
            htmly = get_template(location + '.html')
        except Exception as e:
            print 'Error in MainHandler', e
            return False
        return [plaintext, htmly]

    """
    Required Parameter:
    @body directory has fields type(Welcome, passwd reset), to(User Object)
    """
    def handle(self, mtype, user):
        # Call getTemplate and then Send
        if not mtype or not user:
            return False

        subjects = {
            'welcome': 'Welcome to test',
            'verify': 'Verify your email address',
            'passreset': 'Password reset'
        }
        (plaintext, htmly) = self.getTemplates('mails/' + mtype)
        contxt = Context({ 'username': user.username })

        if self.send(to=[user.email], subject=subjects[mtype], text_body=plaintext, html_body=htmly):
            return True
        else:
            return False

    def thread_run(self, msg):
        msg.send()

    def send(self, to=[], from_email='[email protected]', subject='', text_body='', html_body=''):
        msg = EmailMultiAlternatives(subject, text_body, from_email, to)
        msg.attach_alternative(html_body, "text/html")

        thread = threading.Thread(target=self.thread_run, args=(msg))
        response = thread.start()

        print 'Thread started'
        print response