==============

Sending e-mail

==============

.. module:: django.core.mail

   :synopsis: Helpers to easily send e-mail.

Although Python makes sending e-mail relatively easy via the `smtplib

library`_, Django provides a couple of light wrappers over it. These wrappers

are provided to make sending e-mail extra quick, to make it easy to test

e-mail sending during development, and to provide support for platforms that

can't use SMTP.

The code lives in the ``django.core.mail`` module.

.. _smtplib library: http://docs.python.org/library/smtplib.html

Quick example

=============

In two lines::

    from django.core.mail import send_mail

    send_mail('Subject here', 'Here is the message.', 'from@example.com',

        ['to@example.com'], fail_silently=False)

Mail is sent using the SMTP host and port specified in the

:setting:`EMAIL_HOST` and :setting:`EMAIL_PORT` settings. The

:setting:`EMAIL_HOST_USER` and :setting:`EMAIL_HOST_PASSWORD` settings, if

set, are used to authenticate to the SMTP server, and the

:setting:`EMAIL_USE_TLS` setting controls whether a secure connection is used.

.. note::

    The character set of e-mail sent with ``django.core.mail`` will be set to

    the value of your :setting:`DEFAULT_CHARSET` setting.

send_mail()

===========

.. function:: send_mail(subject, message, from_email, recipient_list, fail_silently=False, auth_user=None, auth_password=None, connection=None)

The simplest way to send e-mail is using

``django.core.mail.send_mail()``.

The ``subject``, ``message``, ``from_email`` and ``recipient_list`` parameters

are required.

    * ``subject``: A string.

    * ``message``: A string.

    * ``from_email``: A string.

    * ``recipient_list``: A list of strings, each an e-mail address. Each

      member of ``recipient_list`` will see the other recipients in the "To:"

      field of the e-mail message.

    * ``fail_silently``: A boolean. If it's ``False``, ``send_mail`` will raise

      an ``smtplib.SMTPException``. See the `smtplib docs`_ for a list of

      possible exceptions, all of which are subclasses of ``SMTPException``.

    * ``auth_user``: The optional username to use to authenticate to the SMTP

      server. If this isn't provided, Django will use the value of the

      :setting:`EMAIL_HOST_USER` setting.

    * ``auth_password``: The optional password to use to authenticate to the

      SMTP server. If this isn't provided, Django will use the value of the

      :setting:`EMAIL_HOST_PASSWORD` setting.

    * ``connection``: The optional e-mail backend to use to send the mail.

      If unspecified, an instance of the default backend will be used.

      See the documentation on :ref:`E-mail backends <topic-email-backends>`

      for more details.

.. _smtplib docs: http://docs.python.org/library/smtplib.html

send_mass_mail()

================

.. function:: send_mass_mail(datatuple, fail_silently=False, auth_user=None, auth_password=None, connection=None)

``django.core.mail.send_mass_mail()`` is intended to handle mass e-mailing.

``datatuple`` is a tuple in which each element is in this format::

    (subject, message, from_email, recipient_list)

``fail_silently``, ``auth_user`` and ``auth_password`` have the same functions

as in :meth:`~django.core.mail.send_mail()`.

Each separate element of ``datatuple`` results in a separate e-mail message.

As in :meth:`~django.core.mail.send_mail()`, recipients in the same

``recipient_list`` will all see the other addresses in the e-mail messages'

"To:" field.

For example, the following code would send two different messages to

two different sets of recipients; however, only one connection to the

mail server would be opened::

    message1 = ('Subject here', 'Here is the message', 'from@example.com, ['first@example.com', 'other@example.com'])

    message2 = ('Another Subject', 'Here is another message', 'from@example.com', ['second@test.com'])

    send_mass_mail((message1, message2), fail_silently=False)

send_mass_mail() vs. send_mail()

--------------------------------

The main difference between :meth:`~django.core.mail.send_mass_mail()` and

:meth:`~django.core.mail.send_mail()` is that

:meth:`~django.core.mail.send_mail()` opens a connection to the mail server

each time it's executed, while :meth:`~django.core.mail.send_mass_mail()` uses

a single connection for all of its messages. This makes

:meth:`~django.core.mail.send_mass_mail()` slightly more efficient.

mail_admins()

=============

.. function:: mail_admins(subject, message, fail_silently=False, connection=None)

``django.core.mail.mail_admins()`` is a shortcut for sending an e-mail to the

site admins, as defined in the :setting:`ADMINS` setting.

``mail_admins()`` prefixes the subject with the value of the

:setting:`EMAIL_SUBJECT_PREFIX` setting, which is ``"[Django] "`` by default.

The "From:" header of the e-mail will be the value of the

:setting:`SERVER_EMAIL` setting.

This method exists for convenience and readability.

mail_managers()

===============

.. function:: mail_managers(subject, message, fail_silently=False, connection=None)

``django.core.mail.mail_managers()`` is just like ``mail_admins()``, except it

sends an e-mail to the site managers, as defined in the :setting:`MANAGERS`

setting.

Examples

========

This sends a single e-mail to john@example.com and jane@example.com, with them

both appearing in the "To:"::

    send_mail('Subject', 'Message.', 'from@example.com',

        ['john@example.com', 'jane@example.com'])

This sends a message to john@example.com and jane@example.com, with them both

receiving a separate e-mail::

    datatuple = (

        ('Subject', 'Message.', 'from@example.com', ['john@example.com']),

        ('Subject', 'Message.', 'from@example.com', ['jane@example.com']),

    )

    send_mass_mail(datatuple)

Preventing header injection

===========================

`Header injection`_ is a security exploit in which an attacker inserts extra

e-mail headers to control the "To:" and "From:" in e-mail messages that your

scripts generate.

The Django e-mail functions outlined above all protect against header injection

by forbidding newlines in header values. If any ``subject``, ``from_email`` or

``recipient_list`` contains a newline (in either Unix, Windows or Mac style),

the e-mail function (e.g. :meth:`~django.core.mail.send_mail()`) will raise

``django.core.mail.BadHeaderError`` (a subclass of ``ValueError``) and, hence,

will not send the e-mail. It's your responsibility to validate all data before

passing it to the e-mail functions.

If a ``message`` contains headers at the start of the string, the headers will

simply be printed as the first bit of the e-mail message.

Here's an example view that takes a ``subject``, ``message`` and ``from_email``

from the request's POST data, sends that to admin@example.com and redirects to

"/contact/thanks/" when it's done::

    from django.core.mail import send_mail, BadHeaderError

    def send_email(request):

        subject = request.POST.get('subject', '')

        message = request.POST.get('message', '')

        from_email = request.POST.get('from_email', '')

        if subject and message and from_email:

            try:

                send_mail(subject, message, from_email, ['admin@example.com'])

            except BadHeaderError:

                return HttpResponse('Invalid header found.')

            return HttpResponseRedirect('/contact/thanks/')

        else:

            # In reality we'd use a form class

            # to get proper validation errors.

            return HttpResponse('Make sure all fields are entered and valid.')

.. _Header injection: http://www.nyphp.org/phundamentals/email_header_injection.php

.. _emailmessage-and-smtpconnection:

The EmailMessage class

======================

.. versionadded:: 1.0

Django's :meth:`~django.core.mail.send_mail()` and

:meth:`~django.core.mail.send_mass_mail()` functions are actually thin

wrappers that make use of the :class:`~django.core.mail.EmailMessage` class.

Not all features of the :class:`~django.core.mail.EmailMessage` class are

available through the :meth:`~django.core.mail.send_mail()` and related

wrapper functions. If you wish to use advanced features, such as BCC'ed

recipients, file attachments, or multi-part e-mail, you'll need to create

:class:`~django.core.mail.EmailMessage` instances directly.

.. note::

    This is a design feature. :meth:`~django.core.mail.send_mail()` and

    related functions were originally the only interface Django provided.

    However, the list of parameters they accepted was slowly growing over

    time. It made sense to move to a more object-oriented design for e-mail

    messages and retain the original functions only for backwards

    compatibility.

:class:`~django.core.mail.EmailMessage` is responsible for creating the e-mail

message itself. The :ref:`e-mail backend <topic-email-backends>` is then

responsible for sending the e-mail.

For convenience, :class:`~django.core.mail.EmailMessage` provides a simple

``send()`` method for sending a single e-mail. If you need to send multiple

messages, the e-mail backend API :ref:`provides an alternative

<topics-sending-multiple-emails>`.

EmailMessage Objects

--------------------

.. class:: EmailMessage

The :class:`~django.core.mail.EmailMessage` class is initialized with the

following parameters (in the given order, if positional arguments are used).

All parameters are optional and can be set at any time prior to calling the

``send()`` method.

    * ``subject``: The subject line of the e-mail.

    * ``body``: The body text. This should be a plain text message.

    * ``from_email``: The sender's address. Both ``fred@example.com`` and

      ``Fred <fred@example.com>`` forms are legal. If omitted, the

      :setting:`DEFAULT_FROM_EMAIL` setting is used.

    * ``to``: A list or tuple of recipient addresses.

    * ``bcc``: A list or tuple of addresses used in the "Bcc" header when

      sending the e-mail.

    * ``connection``: An e-mail backend instance. Use this parameter if

      you want to use the same connection for multiple messages. If omitted, a

      new connection is created when ``send()`` is called.

    * ``attachments``: A list of attachments to put on the message. These can

      be either ``email.MIMEBase.MIMEBase`` instances, or ``(filename,

      content, mimetype)`` triples.

    * ``headers``: A dictionary of extra headers to put on the message. The

      keys are the header name, values are the header values. It's up to the

      caller to ensure header names and values are in the correct format for

      an e-mail message.

For example::

    email = EmailMessage('Hello', 'Body goes here', 'from@example.com',

                ['to1@example.com', 'to2@example.com'], ['bcc@example.com'],

                headers = {'Reply-To': 'another@example.com'})

The class has the following methods:

    * ``send(fail_silently=False)`` sends the message. If a connection was

      specified when the e-mail was constructed, that connection will be used.

      Otherwise, an instance of the default backend will be instantiated and

      used. If the keyword argument ``fail_silently`` is ``True``, exceptions

      raised while sending the message will be quashed.

    * ``message()`` constructs a ``django.core.mail.SafeMIMEText`` object (a

      subclass of Python's ``email.MIMEText.MIMEText`` class) or a

      ``django.core.mail.SafeMIMEMultipart`` object holding the message to be

      sent. If you ever need to extend the

      :class:`~django.core.mail.EmailMessage` class, you'll probably want to

      override this method to put the content you want into the MIME object.

    * ``recipients()`` returns a list of all the recipients of the message,

      whether they're recorded in the ``to`` or ``bcc`` attributes. This is

      another method you might need to override when subclassing, because the

      SMTP server needs to be told the full list of recipients when the message

      is sent. If you add another way to specify recipients in your class, they

      need to be returned from this method as well.

    * ``attach()`` creates a new file attachment and adds it to the message.

      There are two ways to call ``attach()``:

       * You can pass it a single argument that is an

         ``email.MIMEBase.MIMEBase`` instance. This will be inserted directly

         into the resulting message.

       * Alternatively, you can pass ``attach()`` three arguments:

         ``filename``, ``content`` and ``mimetype``. ``filename`` is the name

         of the file attachment as it will appear in the e-mail, ``content`` is

         the data that will be contained inside the attachment and

         ``mimetype`` is the optional MIME type for the attachment. If you

         omit ``mimetype``, the MIME content type will be guessed from the

         filename of the attachment.

         For example::

            message.attach('design.png', img_data, 'image/png')

    * ``attach_file()`` creates a new attachment using a file from your

      filesystem. Call it with the path of the file to attach and, optionally,

      the MIME type to use for the attachment. If the MIME type is omitted, it

      will be guessed from the filename. The simplest use would be::

        message.attach_file('/images/weather_map.png')

.. _DEFAULT_FROM_EMAIL: ../settings/#default-from-email

Sending alternative content types

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

It can be useful to include multiple versions of the content in an e-mail; the

classic example is to send both text and HTML versions of a message. With

Django's e-mail library, you can do this using the ``EmailMultiAlternatives``

class. This subclass of :class:`~django.core.mail.EmailMessage` has an

``attach_alternative()`` method for including extra versions of the message

body in the e-mail. All the other methods (including the class initialization)

are inherited directly from :class:`~django.core.mail.EmailMessage`.

To send a text and HTML combination, you could write::

    from django.core.mail import EmailMultiAlternatives

    subject, from_email, to = 'hello', 'from@example.com', 'to@example.com'

    text_content = 'This is an important message.'

    html_content = '<p>This is an <strong>important</strong> message.</p>'

    msg = EmailMultiAlternatives(subject, text_content, from_email, [to])

    msg.attach_alternative(html_content, "text/html")

    msg.send()

By default, the MIME type of the ``body`` parameter in an

:class:`~django.core.mail.EmailMessage` is ``"text/plain"``. It is good

practice to leave this alone, because it guarantees that any recipient will be

able to read the e-mail, regardless of their mail client. However, if you are

confident that your recipients can handle an alternative content type, you can

use the ``content_subtype`` attribute on the

:class:`~django.core.mail.EmailMessage` class to change the main content type.

The major type will always be ``"text"``, but you can change the

subtype. For example::

    msg = EmailMessage(subject, html_content, from_email, [to])

    msg.content_subtype = "html"  # Main content is now text/html

    msg.send()

.. _topic-email-backends:

E-Mail Backends

===============

.. versionadded:: 1.2

The actual sending of an e-mail is handled by the e-mail backend.

The e-mail backend class has the following methods:

    * ``open()`` instantiates an long-lived e-mail-sending connection.

    * ``close()`` closes the current e-mail-sending connection.

    * ``send_messages(email_messages)`` sends a list of

      :class:`~django.core.mail.EmailMessage` objects. If the connection is

      not open, this call will implicitly open the connection, and close the

      connection afterwards. If the connection is already open, it will be

      left open after mail has been sent.

Obtaining an instance of an e-mail backend

------------------------------------------

The :meth:`get_connection` function in ``django.core.mail`` returns an

instance of the e-mail backend that you can use.

.. currentmodule:: django.core.mail

.. function:: get_connection(backend=None, fail_silently=False, *args, **kwargs)

By default, a call to ``get_connection()`` will return an instance of the

e-mail backend specified in :setting:`EMAIL_BACKEND`. If you specify the

``backend`` argument, an instance of that backend will be instantiated.

The ``fail_silently`` argument controls how the backend should handle errors.

If ``fail_silently`` is True, exceptions during the e-mail sending process

will be silently ignored.

All other arguments are passed directly to the constructor of the

e-mail backend.

Django ships with several e-mail sending backends. With the exception of the

SMTP backend (which is the default), these backends are only useful during

testing and development. If you have special e-mail sending requirements, you

can :ref:`write your own e-mail backend <topic-custom-email-backend>`.

.. _topic-email-smtp-backend:

SMTP backend

~~~~~~~~~~~~

This is the default backend. E-mail will be sent through a SMTP server.

The server address and authentication credentials are set in the

:setting:`EMAIL_HOST`, :setting:`EMAIL_PORT`, :setting:`EMAIL_HOST_USER`,

:setting:`EMAIL_HOST_PASSWORD` and :setting:`EMAIL_USE_TLS` settings in your

settings file.

The SMTP backend is the default configuration inherited by Django. If you

want to specify it explicitly, put the following in your settings::

    EMAIL_BACKEND = 'django.core.mail.backends.smtp.EmailBackend'

.. admonition:: SMTPConnection objects

    Prior to version 1.2, Django provided a

    :class:`~django.core.mail.SMTPConnection` class. This class provided a way

    to directly control the use of SMTP to send e-mail. This class has been

    deprecated in favor of the generic e-mail backend API.

    For backwards compatibility :class:`~django.core.mail.SMTPConnection` is

    still available in ``django.core.mail`` as an alias for the SMTP backend.

    New code should use :meth:`~django.core.mail.get_connection` instead.

.. _topic-email-console-backend:

Console backend

~~~~~~~~~~~~~~~

Instead of sending out real e-mails the console backend just writes the

e-mails that would be send to the standard output. By default, the console

backend writes to ``stdout``. You can use a different stream-like object by

providing the ``stream`` keyword argument when constructing the connection.

To specify this backend, put the following in your settings::

    EMAIL_BACKEND = 'django.core.mail.backends.console.EmailBackend'

This backend is not intended for use in production -- it is provided as a

convenience that can be used during development.

.. _topic-email-file-backend:

File backend

~~~~~~~~~~~~

The file backend writes e-mails to a file. A new file is created for each new

session that is opened on this backend. The directory to which the files are

written is either taken from the :setting:`EMAIL_FILE_PATH` setting or from

the ``file_path`` keyword when creating a connection with

:meth:`~django.core.mail.get_connection`.

To specify this backend, put the following in your settings::

    EMAIL_BACKEND = 'django.core.mail.backends.filebased.EmailBackend'

    EMAIL_FILE_PATH = '/tmp/app-messages' # change this to a proper location

This backend is not intended for use in production -- it is provided as a

convenience that can be used during development.

.. _topic-email-memory-backend:

In-memory backend

~~~~~~~~~~~~~~~~~

The ``'locmem'`` backend stores messages in a special attribute of the

``django.core.mail`` module. The ``outbox`` attribute is created when the

first message is sent. It's a list with an

:class:`~django.core.mail.EmailMessage` instance for each message that would

be send.

To specify this backend, put the following in your settings::

  EMAIL_BACKEND = 'django.core.mail.backends.locmem.EmailBackend'

This backend is not intended for use in production -- it is provided as a

convenience that can be used during development and testing.

.. _topic-email-dummy-backend:

Dummy backend

~~~~~~~~~~~~~

As the name suggests the dummy backend does nothing with your messages. To

specify this backend, put the following in your settings::

   EMAIL_BACKEND = 'django.core.mail.backends.dummy.EmailBackend'

This backend is not intended for use in production -- it is provided as a

convenience that can be used during development.

.. _topic-custom-email-backend:

Defining a custom e-mail backend

--------------------------------

If you need to change how e-mails are sent you can write your own e-mail

backend. The ``EMAIL_BACKEND`` setting in your settings file is then the

Python import path for your backend class.

Custom e-mail backends should subclass ``BaseEmailBackend`` that is located in

the ``django.core.mail.backends.base`` module. A custom e-mail backend must

implement the ``send_messages(email_messages)`` method. This method receives a

list of :class:`~django.core.mail.EmailMessage` instances and returns the

number of successfully delivered messages. If your backend has any concept of

a persistent session or connection, you should also implement the ``open()``

and ``close()`` methods. Refer to ``smtp.EmailBackend`` for a reference

implementation.

.. _topics-sending-multiple-emails:

Sending multiple e-mails

------------------------

Establishing and closing an SMTP connection (or any other network connection,

for that matter) is an expensive process. If you have a lot of e-mails to send,

it makes sense to reuse an SMTP connection, rather than creating and

destroying a connection every time you want to send an e-mail.

There are two ways you tell an e-mail backend to reuse a connection.

Firstly, you can use the ``send_messages()`` method. ``send_messages()`` takes

a list of :class:`~django.core.mail.EmailMessage` instances (or subclasses),

and sends them all using a single connection.