title: smtplib.SMTPServerDisconnected after sending multiple mails in Django
body: <p>I have a blog post objects. After blog post created I have a signal to dispatch emails. And I want to send emails to multiple subscribers.
  I am using google mail as a mail server.
  I put in my settings file some attributes for using mail:</p>
  
  <pre><code>EMAIL_HOST = settings['EMAIL']['HOST']
  EMAIL_PORT = settings['EMAIL']['PORT']
  EMAIL_HOST_USER = settings['EMAIL']['USER']
  EMAIL_HOST_PASSWORD = settings['EMAIL']['PASSWORD']
  EMAIL_USE_TLS = True
  </code></pre>
  
  <p>And function to dispatch mails. Function is a celery task.</p>
  
  <pre><code>@shared_task
  def email_dispatch(heading, text):
      recipients = TheUser.objects.filter(subscription=True)
  
      for recipient in recipients:
          try:
              html_content = render_to_string('mails/email_dispatch.html', {'text': text})
              text_content = strip_tags(html_content)
              subject = '{}'.format(heading)
  
              email = EmailMultiAlternatives(subject, text_content, to=[recipient.id_user.email])
              email.attach_alternative(html_content, 'text/html')
              email.send()
  
              logger.info('Successful processed "{}", sent to: "{}"'.format(count_processed, recipient.id_user.username))
  
          except NoReverseMatch:
              logger.info('Unexpected username: "{}"'.format(recipient.id_user.username))
  
      logger.info('Email dispatching has been finished.')
  </code></pre>
  
  <p>At a first glance, all work okay. When celery task starts executing it dispatches correctly. But after approximately sent ~80 emails I receive </p>
  
  <blockquote>
    <p>smtplib.SMTPServerDisconnected: Connection unexpectedly closed</p>
  </blockquote>
  
  <p>Unfortunately, I didn't found any info about Google Mail restrictions in that case. Maybe I am setting something wrong from Django side or using an incorrect function for this case.</p>
  
  <p>Thank you for any help.</p>