title: Weird Django TypeError: send_mail() takes at least 4 arguments (4 given)
body: <p>I am trying to actually test sending an email using mailtrap.io, and I set up the email server as directed, however, when I try to do the following:</p>
  
  <pre><code>form = InterestedForm(request.POST)
  if form.is_valid():
      name = form.cleaned_data['name']
      email = form.cleaned_data['email']
      subject = "Index form: Interested in Ucodon"
      message = 'Name: ' + name + '\n' + 'Email: ' + email
      recipients=['test@gmail.com']
      send_mail(subject, message, recipients, fail_silently=False)
      thanks = True
  </code></pre>
  
  <p>I get the following error:</p>
  
  <pre><code>TypeError: send_mail() takes at least 4 arguments (4 given)
  </code></pre>
  
  <p>I have even tried the following:</p>
  
  <pre><code>send_mail(subject=subject, message=message, recipients=recipients, fail_silently=False)
  </code></pre>
  
  <p>Also, I have defined EMAIL_HOST_USER. I am currently using EMAIL_HOST='mailtrap.io'.</p>