[Fixed]-Django-registration-redux Manual Account Activation

If you are prepared to switch to django-registration this backend https://django-registration.readthedocs.org/en/2.0.3/simple-workflow.html is close to what you want. You could copy it and just remove the lines that authenticates and logs in the user.

https://github.com/ubernostrum/django-registration/blob/master/registration/backends/simple/views.py