.. _multiple-backends:

Mixing email backends
=====================

Since you are replacing Django's global :setting:`EMAIL_BACKEND`, by default
Anymail will handle **all** outgoing mail, sending everything through your ESP.

You can use Django mail's optional :func:`connection <django.core.mail.get_connection>`
argument to send some mail through your ESP and others through a different system.

This could be useful, for example, to deliver customer emails with the ESP,
but send admin emails directly through an SMTP server:

.. code-block:: python
    :emphasize-lines: 8,10,13,15,19-20,22

    from django.core.mail import send_mail, get_connection

    # send_mail connection defaults to the settings EMAIL_BACKEND, which
    # we've set to Anymail's MailgunBackend. This will be sent using Mailgun:
    send_mail("Thanks", "We sent your order", "sales@example.com", ["customer@example.com"])

    # Get a connection to an SMTP backend, and send using that instead:
    smtp_backend = get_connection('django.core.mail.backends.smtp.EmailBackend')
    send_mail("Uh-Oh", "Need your attention", "admin@example.com", ["alert@example.com"],
              connection=smtp_backend)

    # You can even use multiple Anymail backends in the same app:
    sendgrid_backend = get_connection('anymail.backends.sendgrid.SendGridBackend')
    send_mail("Password reset", "Here you go", "noreply@example.com", ["user@example.com"],
              connection=sendgrid_backend)

    # You can override settings.py settings with kwargs to get_connection.
    # This example supplies credentials to use a SendGrid subuser acccount:
    alt_sendgrid_backend = get_connection('anymail.backends.sendgrid.SendGridBackend',
                                          username='marketing_subuser', password='abc123')
    send_mail("Here's that info", "you wanted", "marketing@example.com", ["prospect@example.com"],
              connection=alt_sendgrid_backend)


You can supply a different connection to Django's
:func:`~django.core.mail.send_mail` and :func:`~django.core.mail.send_mass_mail` helpers,
and in the constructor for an
:class:`~django.core.mail.EmailMessage` or :class:`~django.core.mail.EmailMultiAlternatives`.


(See the :class:`django.utils.log.AdminEmailHandler` docs for more information
on Django's admin error logging.)


You could expand on this concept and create your own EmailBackend that
dynamically switches between other Anymail backends---based on properties of the
message, or other criteria you set. For example, `this gist`_ shows an EmailBackend
that checks ESPs' status-page APIs, and automatically falls back to a different ESP
when the first one isn't working.

.. _this gist:
    https://gist.github.com/tgehrs/58ae571b6db64225c317bf83c06ec312