django-mailer 1.2.1

A reusable Django app for queuing the sending of email

Usage

First, add “mailer” to your INSTALLED_APPS in your settings.py. Run ./manage.py migrate to install models.

Using EMAIL_BACKEND

This is the preferred and easiest way to use django-mailer.

To automatically switch all your mail to use django-mailer, first set EMAIL_BACKEND:

EMAIL_BACKEND = "mailer.backend.DbBackend"

If you were previously using a non-default EMAIL_BACKEND, you need to configure the MAILER_EMAIL_BACKEND setting, so that django-mailer knows how to actually send the mail:

MAILER_EMAIL_BACKEND = "your.actual.EmailBackend"

Now, just use the normal Django mail functions for sending email. These functions will store mail on a queue in the database, which must be sent as below.

Explicitly putting mail on the queue

If you don’t want to send all email through django-mailer, you can send mail using mailer.send_mail, which has the same signature as Django’s send_mail function.

You can also do the following:

# favour django-mailer but fall back to django.core.mail
from django.conf import settings

if "mailer" in settings.INSTALLED_APPS:
    from mailer import send_mail
else:
    from django.core.mail import send_mail

and then just call send_mail like you normally would in Django:

send_mail(subject, message_body, settings.DEFAULT_FROM_EMAIL, recipients)

There is also a convenience function mailer.send_html_mail for creating HTML (this function is not in Django):

send_html_mail(subject, message_plaintext, message_html, settings.DEFAULT_FROM_EMAIL, recipients)

Additionally you can send all the admins as specified in the ADMIN setting by calling:

mail_admins(subject, message_body)

or all managers as defined in the MANAGERS setting by calling:

mail_managers(subject, message_body)

Clear queue with command extensions

With mailer in your INSTALLED_APPS, there will be three new manage.py commands you can run:

• send_mail will clear the current message queue. If there are any failures, they will be marked deferred and will not be attempted again by send_mail.

• retry_deferred will move any deferred mail back into the normal queue (so it will be attempted again on the next send_mail).

• purge_mail_log will remove old successful message logs from the database, to prevent it from filling up your database

You may want to set these up via cron to run regularly:

*       * * * * (/path/to/your/python /path/to/your/manage.py send_mail >> ~/cron_mail.log 2>&1)
0,20,40 * * * * (/path/to/your/python /path/to/your/manage.py retry_deferred >> ~/cron_mail_deferred.log 2>&1)
0 0 * * * (/path/to/your/python /path/to/your/manage.py purge_mail_log 7 >> ~/cron_mail_purge.log 2>&1)

For use in Pinax, for example, that might look like:

* * * * * (cd $PINAX; /usr/local/bin/python2.5 manage.py send_mail >> $PINAX/cron_mail.log 2>&1)
0,20,40 * * * * (cd $PINAX; /usr/local/bin/python2.5 manage.py retry_deferred >> $PINAX/cron_mail_deferred.log 2>&1)
0 0 * * * (cd $PINAX; /usr/local/bin/python2.5 manage.py purge_mail_log 7 >> $PINAX/cron_mail_purge.log 2>&1)

This attempts to send mail every minute with a retry on failure every 20 minutes, and purges the mail log for entries older than 7 days.

manage.py send_mail uses a lock file in case clearing the queue takes longer than the interval between calling manage.py send_mail.

Note that if your project lives inside a virtualenv, you also have to execute this command from the virtualenv. The same, naturally, applies also if you’re executing it with cron. The Pinax documentation explains that in more details.

Using EMAIL_BACKEND

To automatically switch all your mail to use django-mailer, instead of changing imports you can also use the EMAIL_BACKEND feature that was introduced in Django 1.2. In your settings file, you first have to set EMAIL_BACKEND:

EMAIL_BACKEND = "mailer.backend.DbBackend"

If you were previously using a non-default EMAIL_BACKEND, you need to configure the MAILER_EMAIL_BACKEND setting, so that django-mailer knows how to actually send the mail:

MAILER_EMAIL_BACKEND = "your.actual.EmailBackend"

Controlling the delivery process

If you wish to have a finer control over the delivery process, which defaults to deliver everything in the queue, you can use the following 3 variables (default values shown):

MAILER_EMAIL_MAX_BATCH = None  # integer or None
MAILER_EMAIL_MAX_DEFERRED = None  # integer or None
MAILER_EMAIL_THROTTLE = 0  # passed to time.sleep()

These control how many emails are sent successfully before stopping the current run MAILER_EMAIL_MAX_BATCH, after how many failed/deferred emails should it stop MAILER_EMAIL_MAX_DEFERRED and how much time to wait between each email MAILER_EMAIL_THROTTLE.

Unprocessed emails will be evaluated in the following delivery iterations.

Change log

1.2.1

• More helpful admin for Message and MessageLog

• Handle exceptions from really old Django versions

1.2.0

• Save the Message-ID header on Message explicitly to enable finding emails using this identifier.

  This includes a database schema migration.

1.1.0

• Deprecated calling send_mail and send_html_mail using priority kwargs "high", "medium", and "low". Instead you should use PRIORITY_HIGH, PRIORITY_MEDIUM and PRIORITY_LOW from mailer.models.

• Fixed bug with migrations for Django 1.7, which wanted to create a migration to ‘fix’ the EmailField length back down to 75 instead of 254.

1.0.1

• Included migrations - for both South and Django 1.7 native migrations.

  Note:

  • If you use South, you will need at least South 1.0

  • You will need to use ‘–fake’ or ‘–fake-initial’ on existing installations.

  These migrations were supposed to be in 1.0.0 but were omitted due to a packaging error.

1.0.0

• Throttling of email sending

• Django 1.8 support

• Admin tweaks and improvements

• Various other fixes, especially from Renato Alves <[e-mail]> - thank you!

0.1.0

• First PyPI version