Follow these steps to create notifications for administrators:

1. Create the signals.py file, with the following content:

# viral_videos/signals.py
from django.db.models.signals import post_save
from django.dispatch import receiver
from django.template.loader import render_to_string

from .models import ViralVideo


@receiver(post_save, sender=ViralVideo)
def inform_administrators(sender, **kwargs):
    from django.core.mail import mail_admins

    instance = kwargs["instance"]
    created = kwargs["created"]

    if created:
        context = {
            "title": instance.title,
            "link": instance.get_url(),
        }
        plain_text_message = render_to_string(
            'viral_videos/email/administrator/message.txt',
            context)
        html_message = render_to_string(
            'viral_videos/email/administrator/message.html',
            context)
        subject = render_to_string(
            'viral_videos/email/administrator/subject.txt',
            context)

        mail_admins(
            subject=subject.strip(),
            message=plain_text_message,
            html_message=html_message,
            fail_silently=True)

2. Next, we will need a template for the plain text message—something like the following:

{# templates/viral_videos/email/administrator/message.txt #}
A new viral video called "{{ title }}" has been created.
You can preview it at {{ link }}.

3. We will also need a template for the HTML message, as follows:

{# templates/viral_videos/email/administrator/message.html #}
<p>A new viral video called "{{ title }}" has been created.</p>
<p>You can <a href="{{ link }}">preview it here</a>.</p>

4. Then, we will need a template for the email subject, as follows:

{# templates/viral_videos/email/administrator/subject.txt #}
New Viral Video Added

5. Create the apps.py file, with the following content:

# viral_videos/apps.py
from django.apps import AppConfig
from django.utils.translation import ugettext_lazy as _


class ViralVideosAppConfig(AppConfig):
    name = "viral_videos"
    verbose_name = _("Viral Videos")

    def ready(self):
        from .signals import inform_administrators

6. Update the __init__.py file, with the following content:

# viral_videos/__init__.py
default_app_config = "viral_videos.apps.ViralVideosAppConfig"

7. Make sure that you have ADMINS set in the project settings, similar to the following:

# settings.py or config/base.py
ADMINS = (
    ("Admin User", "[email protected]"),
)