============== Sending e-mail ============== Although Python makes sending e-mail relatively easy via the `smtplib library`_, Django provides a couple of light wrappers over it, to make sending e-mail extra quick. The code lives in a single module: ``django.core.mail``. .. _smtplib library: http://www.python.org/doc/current/lib/module-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 `EMAIL_HOST`_ and `EMAIL_PORT`_ settings. The `EMAIL_HOST_USER`_ and `EMAIL_HOST_PASSWORD`_ settings, if set, are used to authenticate to the SMTP server, and the `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 `DEFAULT_CHARSET`_ setting. .. _DEFAULT_CHARSET: ../settings/#default-charset .. _EMAIL_HOST: ../settings/#email-host .. _EMAIL_PORT: ../settings/#email-port .. _EMAIL_HOST_USER: ../settings/#email-host-user .. _EMAIL_HOST_PASSWORD: ../settings/#email-host-password .. _EMAIL_USE_TLS: ../settings/#email-use-tls send_mail() =========== The simplest way to send e-mail is using the function ``django.core.mail.send_mail()``. Here's its definition:: send_mail(subject, message, from_email, recipient_list, fail_silently=False, auth_user=None, auth_password=None) 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 ``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 ``EMAIL_HOST_PASSWORD`` setting. .. _smtplib docs: http://www.python.org/doc/current/lib/module-smtplib.html send_mass_mail() ================ ``django.core.mail.send_mass_mail()`` is intended to handle mass e-mailing. Here's the definition:: send_mass_mail(datatuple, fail_silently=False, auth_user=None, auth_password=None): ``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 ``send_mail()``. Each separate element of ``datatuple`` results in a separate e-mail message. As in ``send_mail()``, recipients in the same ``recipient_list`` will all see the other addresses in the e-mail messages's "To:" field. send_mass_mail() vs. send_mail() -------------------------------- The main difference between ``send_mass_mail()`` and ``send_mail()`` is that ``send_mail()`` opens a connection to the mail server each time it's executed, while ``send_mass_mail()`` uses a single connection for all of its messages. This makes ``send_mass_mail()`` slightly more efficient. mail_admins() ============= ``django.core.mail.mail_admins()`` is a shortcut for sending an e-mail to the site admins, as defined in the `ADMINS setting`_. Here's the definition:: mail_admins(subject, message, fail_silently=False) ``mail_admins()`` prefixes the subject with the value of the `EMAIL_SUBJECT_PREFIX setting`_, which is ``"[Django] "`` by default. The "From:" header of the e-mail will be the value of the `SERVER_EMAIL setting`_. This method exists for convenience and readability. .. _ADMINS setting: ../settings/#admins .. _EMAIL_SUBJECT_PREFIX setting: ../settings/#email-subject-prefix .. _SERVER_EMAIL setting: ../settings/#server-email mail_managers() function ======================== ``django.core.mail.mail_managers()`` is just like ``mail_admins()``, except it sends an e-mail to the site managers, as defined in the `MANAGERS setting`_. Here's the definition:: mail_managers(subject, message, fail_silently=False) .. _MANAGERS setting: ../settings/#managers 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. ``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 manipulator # to get proper validation errors. return HttpResponse('Make sure all fields are entered and valid.') .. _Header injection: http://securephp.damonkohler.com/index.php/Email_Injection The EmailMessage and SMTPConnection classes =========================================== **New in Django development version** Django's ``send_mail()`` and ``send_mass_mail()`` functions are actually thin wrappers that make use of the ``EmailMessage`` and ``SMTPConnection`` classes in ``django.core.mail``. If you ever need to customize the way Django sends e-mail, you can subclass these two classes to suit your needs. .. note:: Not all features of the ``EmailMessage`` class are available through the ``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 ``EmailMessage`` instances directly. This is a design feature. ``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. If you need to add new functionality to the e-mail infrastrcture, sub-classing the ``EmailMessage`` class should make this a simple task. In general, ``EmailMessage`` is responsible for creating the e-mail message itself. ``SMTPConnection`` is responsible for the network connection side of the operation. This means you can reuse the same connection (an ``SMTPConnection`` instance) for multiple messages. E-mail messages ---------------- The ``EmailMessage`` class is initialized as follows:: email = EmailMessage(subject, body, from_email, to, bcc, connection, attachments) All of these parameters are optional. If ``from_email`` is omitted, the value from ``settings.DEFAULT_FROM_EMAIL`` is used. Both the ``to`` and ``bcc`` parameters are lists of addresses, as strings. The ``attachments`` parameter is a list containing either ``(filename, content, mimetype)`` triples of ``email.MIMEBase.MIMEBase`` instances. For example:: email = EmailMessage('Hello', 'Body goes here', 'from@example.com', ['to1@example.com', 'to2@example.com'], ['bcc@example.com']) The class has the following methods: * ``send()`` sends the message, using either the connection that is specified in the ``connection`` attribute, or creating a new connection if none already exists. * ``message()`` constructs a ``django.core.mail.SafeMIMEText`` object (a sub-class 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 `EmailMessage` class, you'll probably want to override this method to put the content you wish 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 sub-classing, 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 which is an ``email.MIMBase.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 email, ``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') SMTP network connections ------------------------- The ``SMTPConnection`` class is initialized with the host, port, username and password for the SMTP server. If you don't specify one or more of those options, they are read from your settings file. If you're sending lots of messages at once, the ``send_messages()`` method of the ``SMTPConnection`` class is useful. It takes a list of ``EmailMessage`` instances (or subclasses) and sends them over a single connection. For example, if you have a function called ``get_notification_email()`` that returns a list of ``EmailMessage`` objects representing some periodic e-mail you wish to send out, you could send this with:: connection = SMTPConnection() # Use default settings for connection messages = get_notification_email() connection.send_messages(messages)