.. _mandrill-backend:

Mandrill
========

Anymail integrates with the `Mandrill <http://mandrill.com/>`__
transactional email service from MailChimp.

.. note:: **Limited Support for Mandrill**

    Anymail is developed to the public Mandrill documentation, but unlike
    other supported ESPs, we are unable to test or debug against the live
    Mandrill APIs. (MailChimp discourages use of Mandrill by "developers,"
    and doesn't offer testing access for packages like Anymail.)

    As a result, Anymail bugs with Mandrill will generally be discovered
    by Anymail's users, in production; Anymail's maintainers often won't
    be able to answer Mandrill-specific questions; and fixes and improvements
    for Mandrill will tend to lag other ESPs.

    If you are integrating only Mandrill, and not considering one of Anymail's
    other ESPs, you might prefer using MailChimp's official
    :pypi:`mandrill` python package instead of Anymail.


Settings
--------

.. rubric:: EMAIL_BACKEND

To use Anymail's Mandrill backend, set:

  .. code-block:: python

      EMAIL_BACKEND = "anymail.backends.mandrill.EmailBackend"

in your settings.py.


.. setting:: ANYMAIL_MANDRILL_API_KEY

.. rubric:: MANDRILL_API_KEY

Required. Your Mandrill API key:

  .. code-block:: python

      ANYMAIL = {
          ...
          "MANDRILL_API_KEY": "<your API key>",
      }

Anymail will also look for ``MANDRILL_API_KEY`` at the
root of the settings file if neither ``ANYMAIL["MANDRILL_API_KEY"]``
nor ``ANYMAIL_MANDRILL_API_KEY`` is set.


.. setting:: ANYMAIL_MANDRILL_WEBHOOK_KEY

.. rubric:: MANDRILL_WEBHOOK_KEY

Required if using Anymail's webhooks. The "webhook authentication key"
issued by Mandrill.
`More info <https://mandrill.zendesk.com/hc/en-us/articles/205583257>`_
in Mandrill's KB.


.. setting:: ANYMAIL_MANDRILL_WEBHOOK_URL

.. rubric:: MANDRILL_WEBHOOK_URL

Required only if using Anymail's webhooks *and* the hostname your
Django server sees is different from the public webhook URL
you provided Mandrill. (E.g., if you have a proxy in front
of your Django server that forwards
"https\://yoursite.example.com" to "http\://localhost:8000/").

If you are seeing :exc:`AnymailWebhookValidationFailure` errors
from your webhooks, set this to the exact webhook URL you entered
in Mandrill's settings.


.. setting:: ANYMAIL_MANDRILL_API_URL

.. rubric:: MANDRILL_API_URL

The base url for calling the Mandrill API. The default is
``MANDRILL_API_URL = "https://mandrillapp.com/api/1.0"``,
which is the secure, production version of Mandrill's 1.0 API.

(It's unlikely you would need to change this.)


.. _mandrill-esp-extra:

esp_extra support
-----------------

To use Mandrill features not directly supported by Anymail, you can
set a message's :attr:`~anymail.message.AnymailMessage.esp_extra` to
a `dict` of parameters to merge into Mandrill's `messages/send API`_ call.
Note that a few parameters go at the top level, but Mandrill expects
most options within a `'message'` sub-dict---be sure to check their
API docs:

  .. code-block:: python

      message.esp_extra = {
          # Mandrill expects 'ip_pool' at top level...
          'ip_pool': 'Bulk Pool',
          # ... but 'subaccount' must be within a 'message' dict:
          'message': {
              'subaccount': 'Marketing Dept.'
          }
      }

Anymail has special handling that lets you specify Mandrill's
`'recipient_metadata'` as a simple, pythonic `dict` (similar in form
to Anymail's :attr:`~anymail.message.AnymailMessage.merge_data`),
rather than Mandrill's more complex list of rcpt/values dicts.
You can use whichever style you prefer (but either way,
recipient_metadata must be in `esp_extra['message']`).

Similary, Anymail allows Mandrill's `'template_content'` in esp_extra
(top level) either as a pythonic `dict` (similar to Anymail's
:attr:`~anymail.message.AnymailMessage.merge_global_data`) or
as Mandrill's more complex list of name/content dicts.

.. _messages/send API:
    https://mandrillapp.com/api/docs/messages.JSON.html#method=send

.. _mandrill-templates:

Batch sending/merge and ESP templates
-------------------------------------

Mandrill offers both :ref:`ESP stored templates <esp-stored-templates>`
and :ref:`batch sending <batch-send>` with per-recipient merge data.

You can use a Mandrill stored template by setting a message's
:attr:`~anymail.message.AnymailMessage.template_id` to the
template's name. Alternatively, you can refer to merge fields
directly in an EmailMessage's subject and body---the message itself
is used as an on-the-fly template.

In either case, supply the merge data values with Anymail's
normalized :attr:`~anymail.message.AnymailMessage.merge_data`
and :attr:`~anymail.message.AnymailMessage.merge_global_data`
message attributes.

  .. code-block:: python

      # This example defines the template inline, using Mandrill's
      # default MailChimp merge *|field|* syntax.
      # You could use a stored template, instead, with:
      #   message.template_id = "template name"
      message = EmailMessage(
          ...
          subject="Your order *|order_no|* has shipped",
          body="""Hi *|name|*,
                  We shipped your order *|order_no|*
                  on *|ship_date|*.""",
          to=["alice@example.com", "Bob <bob@example.com>"]
      )
      # (you'd probably also set a similar html body with merge fields)
      message.merge_data = {
          'alice@example.com': {'name': "Alice", 'order_no': "12345"},
          'bob@example.com': {'name': "Bob", 'order_no': "54321"},
      }
      message.merge_global_data = {
          'ship_date': "May 15",
      }

When you supply per-recipient :attr:`~anymail.message.AnymailMessage.merge_data`,
Anymail automatically forces Mandrill's `preserve_recipients` option to false,
so that each person in the message's "to" list sees only their own email address.

To use the subject or from address defined with a Mandrill template, set the message's
`subject` or `from_email` attribute to `None`.

See the `Mandrill's template docs`_ for more information.

.. _Mandrill's template docs:
    https://mandrill.zendesk.com/hc/en-us/articles/205582507-Getting-Started-with-Templates


.. _mandrill-webhooks:

Status tracking webhooks
------------------------

If you are using Anymail's normalized :ref:`status tracking <event-tracking>`,
setting up Anymail's webhook URL requires deploying your Django project twice:

1. First, follow the instructions to
   :ref:`configure Anymail's webhooks <webhooks-configuration>`. You *must*
   deploy before adding the webhook URL to Mandrill, because it will attempt
   to verify the URL against your production server.

   Follow `Mandrill's instructions`_ to add Anymail's webhook URL in their settings:

      :samp:`https://{random}:{random}@{yoursite.example.com}/anymail/mandrill/tracking/`

        * *random:random* is an :setting:`ANYMAIL_WEBHOOK_AUTHORIZATION` shared secret
        * *yoursite.example.com* is your Django site

   Be sure to check the boxes in the Mandrill settings for the event types you want to receive.
   The same Anymail tracking URL can handle all Mandrill "message" and "change" events.

2. Mandrill will provide you a "webhook authentication key" once it verifies the URL
   is working. Add this to your Django project's Anymail settings under
   :setting:`MANDRILL_WEBHOOK_KEY <ANYMAIL_MANDRILL_WEBHOOK_KEY>`.
   (You may also need to set :setting:`MANDRILL_WEBHOOK_URL <ANYMAIL_MANDRILL_WEBHOOK_URL>`
   depending on your server config.) Then deploy your project again.

Mandrill implements webhook signing on the entire event payload, and Anymail verifies this
signature. Until the correct webhook key is set, Anymail will raise
an exception for any webhook calls from Mandrill (other than the initial validation request).

Mandrill's webhook signature also covers the exact posting URL. Anymail can usually
figure out the correct (public) URL where Mandrill called your webhook. But if you're
getting an :exc:`AnymailWebhookValidationFailure` with a different URL than you
provided Mandrill, you may need to examine your Django :setting:`SECURE_PROXY_SSL_HEADER`,
:setting:`USE_X_FORWARDED_HOST`, and/or :setting:`USE_X_FORWARDED_PORT` settings. If all
else fails, you can set Anymail's :setting:`MANDRILL_WEBHOOK_URL <ANYMAIL_MANDRILL_WEBHOOK_URL>`
to the same public webhook URL you gave Mandrill.

Mandrill will report these Anymail :attr:`~anymail.signals.AnymailTrackingEvent.event_type`\s:
sent, rejected, deferred, bounced, opened, clicked, complained, unsubscribed. Mandrill does
not support delivered events. Mandrill "whitelist" and "blacklist" change events will show up
as Anymail's unknown event_type.

The event's :attr:`~anymail.signals.AnymailTrackingEvent.esp_event` field will be
a `dict` of Mandrill event fields, for a single event. (Although Mandrill calls
webhooks with batches of events, Anymail will invoke your signal receiver separately
for each event in the batch.)

.. _Mandrill's instructions:
    https://mandrill.zendesk.com/hc/en-us/articles/205583217-Introduction-to-Webhooks


.. _migrating-from-djrill:

Migrating from Djrill
---------------------

Anymail has its origins as a fork of the `Djrill`_
package, which supported only Mandrill. If you are migrating
from Djrill to Anymail -- e.g., because you are thinking
of switching ESPs -- you'll need to make a few changes
to your code.

.. _Djrill: https://github.com/brack3t/Djrill

Changes to settings
~~~~~~~~~~~~~~~~~~~

``MANDRILL_API_KEY``
  Will still work, but consider moving it into the :setting:`ANYMAIL`
  settings dict, or changing it to :setting:`ANYMAIL_MANDRILL_API_KEY`.

``MANDRILL_SETTINGS``
  Use :setting:`ANYMAIL_SEND_DEFAULTS` and/or :setting:`ANYMAIL_MANDRILL_SEND_DEFAULTS`
  (see :ref:`send-defaults`).

  There is one slight behavioral difference between :setting:`ANYMAIL_SEND_DEFAULTS`
  and Djrill's ``MANDRILL_SETTINGS``: in Djrill, setting :attr:`tags` or
  :attr:`merge_vars` on a message would completely override any global
  settings defaults. In Anymail, those message attributes are merged with
  the values from :setting:`ANYMAIL_SEND_DEFAULTS`.

``MANDRILL_SUBACCOUNT``
  Set :ref:`esp_extra <mandrill-esp-extra>`
  globally in :setting:`ANYMAIL_SEND_DEFAULTS`:

    .. code-block:: python

        ANYMAIL = {
            ...
            "MANDRILL_SEND_DEFAULTS": {
                "esp_extra": {
                    "message": {
                        "subaccount": "<your subaccount>"
                    }
                }
            }
        }

``MANDRILL_IGNORE_RECIPIENT_STATUS``
  Renamed to :setting:`ANYMAIL_IGNORE_RECIPIENT_STATUS`
  (or just `IGNORE_RECIPIENT_STATUS` in the :setting:`ANYMAIL`
  settings dict).

``DJRILL_WEBHOOK_SECRET`` and ``DJRILL_WEBHOOK_SECRET_NAME``
  Replaced with HTTP basic auth. See :ref:`securing-webhooks`.

``DJRILL_WEBHOOK_SIGNATURE_KEY``
  Use :setting:`ANYMAIL_MANDRILL_WEBHOOK_KEY` instead.

``DJRILL_WEBHOOK_URL``
  Use :setting:`ANYMAIL_MANDRILL_WEBHOOK_URL`, or eliminate if
  your Django server is not behind a proxy that changes hostnames.


Changes to EmailMessage attributes
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

``message.send_at``
  If you are using an aware datetime for
  :attr:`~anymail.message.AnymailMessage.send_at`,
  it will keep working unchanged with Anymail.

  If you are using a date (without a time), or a naive datetime,
  be aware that these now default to Django's current_timezone,
  rather than UTC as in Djrill.

  (As with Djrill, it's best to use an aware datetime
  that says exactly when you want the message sent.)


``message.mandrill_response``
  Anymail normalizes ESP responses, so you don't have to be familiar
  with the format of Mandrill's JSON.
  See :attr:`~anymail.message.AnymailMessage.anymail_status`.

  The *raw* ESP response is attached to a sent message as
  ``anymail_status.esp_response``, so the direct replacement
  for message.mandrill_response is:

    .. code-block:: python

        mandrill_response = message.anymail_status.esp_response.json()

``message.template_name``
  Anymail renames this to :attr:`~anymail.message.AnymailMessage.template_id`.

``message.merge_vars`` and ``message.global_merge_vars``
  Anymail renames these to :attr:`~anymail.message.AnymailMessage.merge_data`
  and :attr:`~anymail.message.AnymailMessage.merge_global_data`, respectively.

``message.use_template_from`` and ``message.use_template_subject``
  With Anymail, set ``message.from_email = None`` or ``message.subject = None``
  to use the values from the stored template.

**Other Mandrill-specific attributes**
  Djrill allowed nearly all Mandrill API parameters to be set
  as attributes directly on an EmailMessage. With Anymail, you
  should instead set these in the message's
  :ref:`esp_extra <mandrill-esp-extra>` dict as described above.

  Although the Djrill style attributes are still supported (for now),
  Anymail will issue a :exc:`DeprecationWarning` if you try to use them.
  These warnings are visible during tests (with Django's default test
  runner), and will explain how to update your code.

  You can also use the following git grep expression to find potential
  problems:

    .. code-block:: console

        git grep -w \
          -e 'async' -e 'auto_html' -e 'auto_text' -e 'from_name' -e 'global_merge_vars' \
          -e 'google_analytics_campaign' -e 'google_analytics_domains' -e 'important' \
          -e 'inline_css' -e 'ip_pool' -e 'merge_language' -e 'merge_vars' \
          -e 'preserve_recipients' -e 'recipient_metadata' -e 'return_path_domain' \
          -e 'signing_domain' -e 'subaccount' -e 'template_content' -e 'template_name' \
          -e 'tracking_domain' -e 'url_strip_qs' -e 'use_template_from' -e 'use_template_subject' \
          -e 'view_content_link'


**Inline images**
  Djrill (incorrectly) used the presence of a :mailheader:`Content-ID`
  header to decide whether to treat an image as inline. Anymail
  looks for :mailheader:`Content-Disposition: inline`.

  If you were constructing MIMEImage inline image attachments
  for your Djrill messages, in addition to setting the Content-ID,
  you should also add::

      image.add_header('Content-Disposition', 'inline')

  Or better yet, use Anymail's new :ref:`inline-images`
  helper functions to attach your inline images.


Changes to webhooks
~~~~~~~~~~~~~~~~~~~

Anymail uses HTTP basic auth as a shared secret for validating webhook
calls, rather than Djrill's "secret" query parameter. See
:ref:`securing-webhooks`. (A slight advantage of basic auth over query
parameters is that most logging and analytics systems are aware of the
need to keep auth secret.)

Anymail replaces `djrill.signals.webhook_event` with
`anymail.signals.tracking` for delivery tracking events.
(It does not currently handle inbound message webhooks.)
Anymail parses and normalizes
the event data passed to the signal receiver: see :ref:`event-tracking`.

The equivalent of Djrill's ``data`` parameter is available
to your signal receiver as
:attr:`event.esp_event <anymail.signals.AnymailTrackingEvent.esp_event>`,
and for most events, the equivalent of Djrill's ``event_type`` parameter
is `event.esp_event['event']`. But consider working with Anymail's
normalized :class:`~anymail.signals.AnymailTrackingEvent` instead.