django/docs/email.txt

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==============
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)
.. note::
The character set of email sent with ``django.core.mail`` will be set to
the value of your `DEFAULT_CHARSET setting`_.
.. _DEFAULT_CHARSET setting: ../settings/#DEFAULT_CHARSET
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=EMAIL_HOST_USER,
auth_password=EMAIL_HOST_PASSWORD)
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=EMAIL_HOST_USER, auth_password=EMAIL_HOST_PASSWORD):
``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: http://www.djangoproject.com/documentation/settings/#admins
.. _EMAIL_SUBJECT_PREFIX setting: http://www.djangoproject.com/documentation/settings/#email-subject-prefix
.. _SERVER_EMAIL setting: http://www.djangoproject.com/documentation/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: http://www.djangoproject.com/documentation/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