[Fixed]-Django form checking

You can enforce server level validation on django forms:
https://docs.djangoproject.com/en/dev/ref/forms/validation/#cleaning-and-validating-fields-that-depend-on-each-other

From the docs for django 1.8:

from django import forms

class ContactForm(forms.Form):
    # Everything as before.
    ...

    def clean(self):
        cleaned_data = super(ContactForm, self).clean()
        cc_myself = cleaned_data.get("cc_myself")
        subject = cleaned_data.get("subject")

        if cc_myself and subject:
            # Only do something if both fields are valid so far.
            if "help" not in subject:
                raise forms.ValidationError(
                    "Did not send for 'help' in the subject despite "
                    "CC'ing yourself."
                )