Nuntius

Nuntius is a newsletter / push notification campaign application for Django.

Nuntius integrates with your Django project. It is very agnostic about your subscribers and subscriber lists models.

It features Mosaico, a drag-and-drop email editor, for sending beautiful emails to your subscribers and push notification support through Apple Push Notification service (APNs) and Google Cloud Messaging (GCM).

How it works

Nuntius is agnostic about your subscribers model. You can use your current use model, as long as it implements a few required methods.

To allow your end-users to choose recipients, it is your choice to implement one or more "segment" models. Segment models implement a required method get_subscribers_queryset.

You can then create campaigns in the Django admin panel, and send them to existing segments.

Installation

1. Add "push_notifications" and "nuntius" to your INSTALLED_APPS setting like this:

       INSTALLED_APPS = [
           'django.contrib.admin',
           'django.contrib.auth',
           'django.contrib.contenttypes',
           'django.contrib.sessions',
           'django.contrib.messages',
           'django.contrib.staticfiles',
           ...
           'push_notifications',
           'nuntius',
       ]

2. Include Nuntius urlconf in your project urls.py like this:

       path('nuntius/', include('nuntius.urls')),

3. Define your subscriber model so it works with Nuntius. You must inherit from nuntius.models.AbstractSubscriber and implement all the necessary methods. An easy way to do this is to use directly or to extend BaseSubscriber, but you can implement the methods of AbstractSubscriber the way you want.

   Here are the methods you must implement :

   • get_subscriber_status() must return one of AbstractSubscriber.STATUS_CHOICES. You can also simply define a subscriber_status attribute.

   • get_subscriber_email() must return a unique email address for the subscriber. You can also simply define an email attribute.

   • get_subscriber_data() must return the dictionnary of values which can be used as substitution in the emails. Default is {"email": self.get_subscriber_email()}.

   • get_subscriber_push_devices() (optional) must return a list of django-push-notifications.APNSDevice and django-push-notifications.GCMDevice model instances (cf. the django-push-notifications documentation)

4. Tell Nuntius how to find your subscriber model in settings.py

   NUNTIUS_SUBSCRIBER_MODEL = 'myapp.MySubscriberModel'

5. Launch the nuntius worker in the background. In a production setting, this should be done through a process monitor like upstart or systemd.

   export DJANGO_SETTINGS_MODULE=myapp.settings
   python ./manage.py nuntius_worker

6. Unless you are using a custom admin site, admin panels for Nuntius will be autodiscovered and added to you admin site. If you use a custom admin site, you need to register Nuntius models with something like:

   admin_site.register(nuntius.models.Campaign, nuntius.admin.CampaignAdmin)
   admin_site.register(nuntius.models.CampaignSentEvent, nuntius.admin.CampaignSentEventAdmin)

Other settings

Use NUNTIUS_DEFAULT_FROM_EMAIL, NUNTIUS_DEFAULT_FROM_NAME, NUNTIUS_DEFAULT_REPLY_TO_EMAIL, NUNTIUS_DEFAULT_REPLY_TO_NAME to change default field values in the admin form.

Use NUNTIUS_ENABLED_CAMPAIGN_TYPES to choose which types of campaign you want to enable by default (email default, push or email,push)

In order to use push notifications, NUNTIUS_PUSH_NOTIFICATION_SETTINGS must be specified (cf. the django-push-notifications documentation)

NUNTIUS_PUSH_NOTIFICATIONS_SETTINGS = {
    "FCM_API_KEY": "[your api key]",
    "GCM_API_KEY": "[your api key]",
    "APNS_CERTIFICATE": "/path/to/your/certificate.pem",
    "APNS_TOPIC": "com.example.push_test",
    # ...
}

Advanced usage

List segments

If you want to have more control on your recipients, you can create a segment model.

One example of segment is a simple model which holds a Many-to-Many relation to subscribers.

Another example is a segment model which filters subscribers depending on the date of their last login :

from django.db import models
from django.db.models import fields
from datetime import datetime

from nuntius.models import BaseSegment


class LastLoginDateSegment(BaseSegment, models.Model):
     last_login_duration = fields.DurationField()
     
     def get_display_name(self):
         return f'Last login : {str(datetime.now() - self.last_login_duration)}'
         
     def get_subscribers_queryset(self):
        return MySubscriberClass.objects.filter(last_login__gt=datetime.now() - self.last_login_duration)
        
     def get_subscribers_count(self):
        return MySubscriberClass.objects.filter(last_login__gt=datetime.now() - self.last_login_duration, subscribed=True)

• get_subscribers_queryset is allowed to return subscribers regardless of their subscriber_status, as get_subscriber_status will be called on each instance.
• get_subscribers_count is only there for convenience in the admin panel, it does not have to be accurate. If you want to have it accurate, you should however take your subscribers status into account.

Then, add your segment model to Nuntius settings :

NUNTIUS_SEGMENT_MODEL = 'myapp.lastlogindatesegment'

Custom template

You can write your own Mosaico template to fit your needs. To make it available in the admin, list the public URL path of the template in NUNTIUS_MOSAICO_TEMPLATES. The template can be served by Django static files system, or any other way at your preference.

NUNTIUS_MOSAICO_TEMPLATES = [
    ("/static/mosaico_templates/versafix-2/template-versafix-2.html", "Custom template")
]

Sending parameters

The worker will spawn several subprocesses to speed up the sending of campaigns. The number of processes that will send emails concurrently can be configured using the NUNTIUS_MAX_CONCURRENT_SENDERS setting.

Most ESP enforce a maximum send rate. Nuntius won't sent messages faster thanNUNTIUS_MAX_SENDING_RATE, in messages per second.

When using SMTP, some ESP limit the number of emails that can be sent using a single connection. NUNTIUS_MAX_MESSAGES_PER_CONNECTION will force Nuntius to reset the connection after sending that many messages.

The Nuntius worker checks every NUNTIUS_POLLING_INTERVAL seconds if any sending has been scheduled or canceled. The default value of 2 seconds should be find for most usages.

To help you configure these parameters, you can send SIGUSR1 to the main worker process and it will print sending statistics on stderr. Pay special attention to the current sending rate and to the current bucket capacity: if your sending rate is lower than the maximum you configured, it most likely means the value you chose for NUNTIUS_MAX_CONCURRENT_SENDERS is not high enough given the latency you're getting with your ESP.

ESP and Webhooks

Maintaining your own SMTP server to send your newsletter is probably a bad idea if you have more than a few subscribers. You can use Anymail along with Nuntius in order to use an email service provider. Anymail supports a lot of ESP, like Amazon SES, Mailgun, Mailjet, Postmark, SendGrid, SendinBlue, or SparkPost.

Refer to the steps in Anymail 1-2-3 to install Anymail. If you want to configure Anymail just for Nuntius and keep the default email backend for other usage, you can use the setting NUNTIUS_EMAIL_BACKEND rather than the default EMAIL_BACKEND.

In addition, configuring Nuntius with Anymail will allow you to use ESP tracking features and to track status of your email once it is sent.

Webhooks

Configuring webhhoks allows Nuntius to track email status and to give you statistics on campaign, as well as updating subscriber status when they bounce.

1. Configure email tracking as described in Anymail documentation.
2. Implement the method set_subscriber_status(self, email, status) on your subscriber model manager.

Nuntius will automatically listen to Anymail signals and call this method if needed.

Handling of non-nuntius events (optional)

If you send emails to your subscribers by other means than Nuntius (for example, transactional emails), you will receive webhooks events which are not related to a campaign you sent. By default, Nuntius will create a campaign result event recording the email and the event type, but it will not link it to a campaign nor to a subscriber model.

If you want your events to always be linked to a subscriber model, you must implement a get_subscriber(self, email_address) method on your subscriber model manager.

BaseSubscriberManager

Nuntius is packaged with a BaseSubscriberManager, which implements both set_subscriber_status and get_subscriber, assuming you have an email field on your subscriber model. This is the default manager used by BaseSubscriber.

Bounce handling

Most ESP gives you a reputation based on your hard bounce rate. Mosaico handles bounces smartly to change your subscribers status when necessary.

If Nuntius receive a bounce event on an email address which has no other sending event, set_subscriber_status(email, status) is called with AbstractSubscriber.STATUS_BOUNCED.

If a successful sending event exists for this address, three parameters are taken into account :

• if during the last duration days, there has been no more bounces than limit and at least one successful sending, no action is taken
• if there has been at least one successful sending in the last consecutive events, no action is taken
• otherwise, set_subscriber_status(email, status) is called with AbstractSubscriber.STATUS_BOUNCED

You can change thoses default values :

NUNTIUS_BOUNCE_PARAMS = {
    "consecutive": 1,
    "duration": 7,
    "limit": 3
}

Example :

• You send 3 campaigns a week. After a few months, a subscriber has a full mailbox. On first and second bounced campaign, no action is taken because there is a successful sending in the last 7 days, and no more than 3 bounces. On the third campaign, if the user has empty their mailbox, everything is fine. Otherwise, the subscriber is marked as permanently bounced.
• You send one campaign a day. A user has a buggy email server. This week, the user has already 3 bounces. When you receive the 4th bounce, if there has been a successful sending just before, everything is fine. Otherwise, the subscriber is marked as permanently bounced.

Tracking

Opening and clicks are tracked by adding a white pixel and replacing links in emails, and by using a proxy URL on push notification clicks.

Nuntius also adds UTM parameters to every URL with the following values:

• utm_source: "nuntius"
• utm_medium: "email"
• utm_campaign: value configured by user at the campaign level
• utm_content: "link-{number}" based on the link position in the email
• utm_term: attribute utm_term of the segment object, or empty string if attribute does not exist

In some situations, two details may be important for you:

1. utm_campaign, utm_content, and utm_term, those are just defaults values, and can also be set directly on the link. utm_source and utm_medium will always be overwritten.
2. utm_content and utm_term are set at sending time and cannot change afterwards. utm_campaign is set at click time, during the redirection from nuntius tracking URL to target URL, so if you change the value at the campaign level after sending, the value will change for all new clicks.

License

Copyright is owned by Jill Royer and Arthur Cheysson.

You can use Nuntius under GPLv3 terms.