title: Django EmailField accepts invalid values
body: <p>I'm currently using the default <code>EmailField</code> attribute on my form. The issue I'm running into is that the form considers an invalid email such as <code>name@mail.56</code> to be valid. Do I need to implement my own <code>validators</code> on this field to make it work correctly?</p>
  
  <p>I was under the impression that having:</p>
  
  <pre><code>#models.py
  email = models.EmailField(max_length=254, blank=False, unique=True,
          error_messages={'required': 'Please provide your email address.',
                          'unique': 'An account with this email exist.'},)
  </code></pre>
  
  <p>Or having:</p>
  
  <pre><code>#forms.py
  email = forms.EmailField()
  </code></pre>
  
  <p>will take care of this type of validation for me but it doesn't seem so.</p>