title: BCC all recipients with EmailMultiAlternatives
body: <p>I have this method that I use to send mass emails:</p>
  
  <pre><code>def send_mass_html_mail(datatuple, fail_silently=False, user=None, password=None, connection=None):
      connection = connection or get_connection(username=user, password=password, fail_silently=fail_silently)
      messages = []
      for subject, text, html, from_email, recipient in datatuple:
          message = EmailMultiAlternatives(subject, text, from_email, recipient)
          message.attach_alternative(html, 'text/html')
          messages.append(message)
      return connection.send_messages(messages)
  </code></pre>
  
  <p>I want to be able to BCC everyone. That is, instead of having everyone's email in the recipients, I would like to hide everyone's email address.</p>
  
  <p>I tried to just make the to email blank and just add all of the recipients to the BCC kwargs, but it still puts everyone's email in the TO field.</p>
  
  <pre><code>def send_mass_html_mail(datatuple, fail_silently=False, user=None, password=None, connection=None):
      connection = connection or get_connection(username=user, password=password, fail_silently=fail_silently)
      messages = []
      for subject, text, html, from_email, recipient in datatuple:
          message = EmailMultiAlternatives(subject, text, from_email, [], bcc=recipient)
          message.attach_alternative(html, 'text/html')
          messages.append(message)
      return connection.send_messages(messages)
  </code></pre>
  
  <p>What am I doing wrong? Do I have to send each email individually?</p>
  
  <p><strong>Edit:</strong></p>
  
  <p>I wound up just iterating through the recipient list and sending off emails separately. I don't know why it didn't work, but I couldn't afford to spend hours on this. It works for me because the app sends emails to a max of 25 people at a time. </p>
  
  <p>I still don't know why this didn't work. Does <code>EmailMultiAlternatives</code> need something in the TO field? I looked at the <code>EmailMultiAlternatives</code> and the <code>EmailMessage</code> source code, and it seems like it'd send emails without anyone in that field. There's something off about my code, but I can't identify what. </p>