E-Mail enumeration through the login form

[ProfessorLogout]

I've noticed, while building an app using django-magiclink, that the behavior of the Login view differs between a valid and invalid email addresses.
Depending on the context of the application this could be bad, as it enables third parties to enumerate valid account addresses.

Testing possible remediations I've subclassed the Login view in my app and do something like this currently:

class CustomLogin(Login):
    # ...
    def post(self, request, *args, **kwargs):
        logout(request)
        context = self.get_context_data(**kwargs)
        context['require_signup'] = settings.REQUIRE_SIGNUP
        form = LoginForm(request.POST)
        if not form.is_valid():
            if form.errors.get("email", False) and settings.NO_EMAIL_ENUMERATION:  # This could be a good setting to disable by default
                if len(form.errors) == 1:
                    sent_url = get_url_path(settings.LOGIN_SENT_REDIRECT)
                    return HttpResponseRedirect(sent_url)
                form.errors.pop("email")
            context['login_form'] = form
            return self.render_to_response(context)
        # ...

I'd be happy to contribute some improvements in that direction if this fits with whats best for the project, just let me know.