Sending email¶
Although Python provides a mail sending interface via the smtplib
module, Django provides a couple of light wrappers over it. These wrappers are
provided to make sending email extra quick, to help test email sending during
development, and to provide support for platforms that can’t use SMTP.
The code lives in the django.core.mail module.
Quick examples¶
Use send_mail() for straightforward email sending. For example, to send a
plain text message:
from django.core.mail import send_mail
send_mail(
"Subject here",
"Here is the message.",
"from@example.com",
["to@example.com"],
fail_silently=False,
)
When additional email sending functionality is needed, use
EmailMessage or EmailMultiAlternatives. For example, to send
a multipart email that includes both HTML and plain text versions with a
specific template and custom headers, you can use the following approach:
from django.core.mail import EmailMultiAlternatives
from django.template.loader import render_to_string
# First, render the plain text content.
text_content = render_to_string(
"templates/emails/my_email.txt",
context={"my_variable": 42},
)
# Secondly, render the HTML content.
html_content = render_to_string(
"templates/emails/my_email.html",
context={"my_variable": 42},
)
# Then, create a multipart email instance.
msg = EmailMultiAlternatives(
subject="Subject here",
body=text_content,
from_email="from@example.com",
to=["to@example.com"],
headers={"List-Unsubscribe": "<mailto:unsub@example.com>"},
)
# Lastly, attach the HTML content to the email instance and send.
msg.attach_alternative(html_content, "text/html")
msg.send()
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 and EMAIL_USE_SSL settings control whether
a secure connection is used.
Note
The character set of email sent with django.core.mail will be set to
the value of your DEFAULT_CHARSET setting.
send_mail()¶
- send_mail(subject, message, from_email, recipient_list, *, fail_silently=False, auth_user=None, auth_password=None, connection=None, html_message=None)[source]¶
In most cases, you can send email 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. IfNone, Django will use the value of theDEFAULT_FROM_EMAILsetting.recipient_list: A list of strings, each an email address. Each member ofrecipient_listwill see the other recipients in the “To:” field of the email message.
The following parameters are optional, and must be given as keyword arguments if used.
fail_silently: A boolean. When it’sFalse,send_mail()will raise ansmtplib.SMTPExceptionif an error occurs. See thesmtplibdocs for a list of possible exceptions, all of which are subclasses ofSMTPException.auth_user: The optional username to use to authenticate to the SMTP server. If this isn’t provided, Django will use the value of theEMAIL_HOST_USERsetting.auth_password: The optional password to use to authenticate to the SMTP server. If this isn’t provided, Django will use the value of theEMAIL_HOST_PASSWORDsetting.connection: The optional email backend to use to send the mail. If unspecified, an instance of the default backend will be used. See the documentation on Email backends for more details.html_message: Ifhtml_messageis provided, the resulting email will be a multipart/alternative email withmessageas the text/plain content type andhtml_messageas the text/html content type.
The return value will be the number of successfully delivered messages (which
can be 0 or 1 since it can only send one message).
Deprecated since version 6.0: Passing fail_silently and later parameters as positional arguments is
deprecated.
send_mass_mail()¶
- send_mass_mail(datatuple, *, fail_silently=False, auth_user=None, auth_password=None, connection=None)[source]¶
django.core.mail.send_mass_mail() is intended to handle mass emailing.
datatuple is a tuple in which each element is in this format:
(subject, message, from_email, recipient_list)
fail_silently, auth_user, auth_password and connection have the
same functions as in send_mail(). They must be given as keyword arguments
if used.
Each separate element of datatuple results in a separate email message.
As in send_mail(), recipients in the same recipient_list will all see
the other addresses in the email 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)
The return value will be the number of successfully delivered messages.
Deprecated since version 6.0: Passing fail_silently and later parameters as positional arguments is
deprecated.
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 email to the
site admins, as defined in the ADMINS setting.
mail_admins() prefixes the subject with the value of the
EMAIL_SUBJECT_PREFIX setting, which is "[Django] " by default.
The “From:” header of the email will be the value of the
SERVER_EMAIL setting.
This method exists for convenience and readability.
If html_message is provided, the resulting email will be a
multipart/alternative email with message as the
text/plain content type and html_message as the
text/html content type.
Deprecated since version 6.0: Passing fail_silently and later parameters as positional arguments is
deprecated.
mail_managers()¶
- mail_managers(subject, message, *, fail_silently=False, connection=None, html_message=None)[source]¶
django.core.mail.mail_managers() is just like mail_admins(), except it
sends an email to the site managers, as defined in the MANAGERS
setting.
Deprecated since version 6.0: Passing fail_silently and later parameters as positional arguments is
deprecated.
Examples¶
This sends a single email 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 email:
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 email headers to control the “To:” and “From:” in email messages that your scripts generate.
The Django email 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 email function (e.g. send_mail()) will raise ValueError and,
hence, will not send the email. It’s your responsibility to validate all data
before passing it to the email functions.
If a message contains headers at the start of the string, the headers will
be printed as the first bit of the email 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
from django.http import HttpResponse, HttpResponseRedirect
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 ValueError:
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.")
Older versions raised django.core.mail.BadHeaderError for some
invalid headers. This has been replaced with ValueError.
The EmailMessage class¶
Django’s send_mail() and send_mass_mail() functions are actually
thin wrappers that make use of the EmailMessage class.
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 email,
you’ll need to create EmailMessage instances directly.
Note
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 email messages and retain the
original functions only for backwards compatibility.
EmailMessage is responsible for creating the email message itself. The
email backend is then responsible for sending the
email.
For convenience, EmailMessage provides a send()
method for sending a single email. If you need to send multiple messages, the
email backend API provides an alternative.
EmailMessage Objects¶
- class EmailMessage[source]¶
The
EmailMessageclass is initialized with the following parameters. All parameters are optional and can be set at any time prior to calling thesend()method.The first four parameters can be passed as positional or keyword arguments, but must be in the given order if positional arguments are used:
subject: The subject line of the email.body: The body text. This should be a plain text message.from_email: The sender’s address. Bothfred@example.comand"Fred" <fred@example.com>forms are legal. If omitted, theDEFAULT_FROM_EMAILsetting is used.to: A list or tuple of recipient addresses.
The following parameters must be given as keyword arguments if used:
cc: A list or tuple of recipient addresses used in the “Cc” header when sending the email.bcc: A list or tuple of addresses used in the “Bcc” header when sending the email.reply_to: A list or tuple of recipient addresses used in the “Reply-To” header when sending the email.attachments: A list of attachments to put on the message. Each can be an instance ofMIMEPartorEmailAttachment, or a tuple with attributes(filename, content, mimetype).Changed in Django 6.0:Support for
MIMEPartobjects in theattachmentslist was added.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 email message. The corresponding attribute isextra_headers.connection: An email backend instance. Use this parameter if you are sending theEmailMessageviasend()and you want to use the same connection for multiple messages. If omitted, a new connection is created whensend()is called. This parameter is ignored when using send_messages().
Deprecated since version 6.0: Passing all except the first four parameters as positional arguments is deprecated.
For example:
from django.core.mail import EmailMessage email = EmailMessage( subject="Hello", body="Body goes here", from_email="from@example.com", to=["to1@example.com", "to2@example.com"], bcc=["bcc@example.com"], reply_to=["another@example.com"], headers={"Message-ID": "foo"}, )
The class has the following methods:
- send(fail_silently=False)[source]¶
Sends the message. If a connection was specified when the email was constructed, that connection will be used. Otherwise, an instance of the default backend will be instantiated and used. If the keyword argument
fail_silentlyisTrue, exceptions raised while sending the message will be quashed. An empty list of recipients will not raise an exception. It will return1if the message was sent successfully, otherwise0.
- message(policy=email.policy.default)[source]¶
Constructs and returns a Python
email.message.EmailMessageobject representing the message to be sent.The keyword argument
policyallows specifying the set of rules for updating and serializing the representation of the message. It must be anemail.policy.Policyobject. Defaults toemail.policy.default. In certain cases you may want to useSMTP,SMTPUTF8or a custom policy. For example,django.core.mail.backends.smtp.EmailBackenduses theSMTPpolicy to ensure\r\nline endings as required by the SMTP protocol.If you ever need to extend Django’s
EmailMessageclass, you’ll probably want to override this method to put the content you want into the Python EmailMessage object.Changed in Django 6.0:The
policykeyword argument was added and the return type was updated to an instance ofEmailMessage.
- recipients()[source]¶
Returns a list of all the recipients of the message, whether they’re recorded in the
to,ccorbccattributes. 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(filename, content, mimetype)[source]¶
- attach(mimepart)
Creates a new attachment and adds it to the message. There are two ways to call
attach():You can pass it three arguments:
filename,contentandmimetype.filenameis the name of the file attachment as it will appear in the email,contentis the data that will be contained inside the attachment andmimetypeis the optional MIME type for the attachment. If you omitmimetype, the MIME content type will be guessed from the filename of the attachment.For example:
message.attach("design.png", img_data, "image/png")
If you specify a
mimetypeof message/rfc822,contentcan be adjango.core.mail.EmailMessageor Python’semail.message.EmailMessageoremail.message.Message.For a
mimetypestarting with text/, content is expected to be a string. Binary data will be decoded using UTF-8, and if that fails, the MIME type will be changed to application/octet-stream and the data will be attached unchanged.Or for attachments requiring additional headers or parameters, you can pass
attach()a single PythonMIMEPartobject. This will be attached directly to the resulting message. For example, to attach an inline image with a Content-ID:cid = email.utils.make_msgid() inline_image = email.message.MIMEPart() inline_image.set_content( image_data_bytes, maintype="image", subtype="png", disposition="inline", cid=f"<{cid}>", ) message.attach(inline_image) message.attach_alternative(f'… <img src="cid:${cid}"> …', "text/html")
Python’s
email.contentmanager.set_content()documentation describes the supported arguments forMIMEPart.set_content().Changed in Django 6.0:Support for
MIMEPartattachments was added.Deprecated since version 6.0: Support for
email.mime.base.MIMEBaseattachments is deprecated. UseMIMEPartinstead.
- attach_file(path, mimetype=None)[source]¶
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. You can use it like this:
message.attach_file("/images/weather_map.png")
For MIME types starting with text/, binary data is handled as in
attach().
- class EmailAttachment¶
A named tuple to store attachments to an email.
The named tuple has the following indexes:
filenamecontentmimetype
Sending alternative content types¶
Sending multiple content versions¶
It can be useful to include multiple versions of the content in an email; the
classic example is to send both text and HTML versions of a message. With
Django’s email library, you can do this using the
EmailMultiAlternatives class.
- class EmailMultiAlternatives[source]¶
A subclass of
EmailMessagethat allows additional versions of the message body in the email via theattach_alternative()method. This directly inherits all methods (including the class initialization) fromEmailMessage.- alternatives¶
A list of
EmailAlternativenamed tuples. This is particularly useful in tests:self.assertEqual(len(msg.alternatives), 1) self.assertEqual(msg.alternatives[0].content, html_content) self.assertEqual(msg.alternatives[0].mimetype, "text/html")
Alternatives should only be added using the
attach_alternative()method, or passed to the constructor.
- attach_alternative(content, mimetype)[source]¶
Attach an alternative representation of the message body in the email.
For example, to send a text and HTML combination, you could write:
from django.core.mail import EmailMultiAlternatives subject = "hello" from_email = "from@example.com" to = "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()
- body_contains(text)[source]¶
Returns a boolean indicating whether the provided
textis contained in the emailbodyand in all attached MIME typetext/*alternatives.This can be useful when testing emails. For example:
def test_contains_email_content(self): subject = "Hello World" from_email = "from@example.com" to = "to@example.com" msg = EmailMultiAlternatives(subject, "I am content.", from_email, [to]) msg.attach_alternative("<p>I am content.</p>", "text/html") self.assertIs(msg.body_contains("I am content"), True) self.assertIs(msg.body_contains("<p>I am content.</p>"), False)
- class EmailAlternative¶
A named tuple to store alternative versions of email content.
The named tuple has the following indexes:
contentmimetype
Updating the default content type¶
By default, the MIME type of the body parameter in an EmailMessage
is "text/plain". It is good practice to leave this alone, because it
guarantees that any recipient will be able to read the email, 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 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()
Email backends¶
The actual sending of an email is handled by the email backend.
The email backend class has the following methods:
open()instantiates a long-lived email-sending connection.close()closes the current email-sending connection.send_messages(email_messages)sends a list ofEmailMessageobjects. If the connection is not open, this call will implicitly open the connection, and close the connection afterward. If the connection is already open, it will be left open after mail has been sent.
It can also be used as a context manager, which will automatically call
open() and close() as needed:
from django.core import mail
with mail.get_connection() as connection:
mail.EmailMessage(
subject1,
body1,
from1,
[to1],
connection=connection,
).send()
mail.EmailMessage(
subject2,
body2,
from2,
[to2],
connection=connection,
).send()
Obtaining an instance of an email backend¶
The get_connection() function in django.core.mail returns an
instance of the email backend that you can use.
By default, a call to get_connection() will return an instance of the
email backend specified in EMAIL_BACKEND. If you specify the
backend argument, an instance of that backend will be instantiated.
The keyword-only fail_silently argument controls how the backend should
handle errors. If fail_silently is True, exceptions during the email
sending process will be silently ignored.
All other keyword arguments are passed directly to the constructor of the email backend.
Django ships with several email 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 email sending requirements, you can write your own email backend.
Deprecated since version 6.0: Passing fail_silently as positional argument is deprecated.
SMTP backend¶
- class backends.smtp.EmailBackend(host=None, port=None, username=None, password=None, use_tls=None, fail_silently=False, use_ssl=None, timeout=None, ssl_keyfile=None, ssl_certfile=None, **kwargs)¶
This is the default backend. Email will be sent through a SMTP server.
The value for each argument is retrieved from the matching setting if the argument is
None:host:EMAIL_HOSTport:EMAIL_PORTusername:EMAIL_HOST_USERpassword:EMAIL_HOST_PASSWORDuse_tls:EMAIL_USE_TLSuse_ssl:EMAIL_USE_SSLtimeout:EMAIL_TIMEOUTssl_keyfile:EMAIL_SSL_KEYFILEssl_certfile:EMAIL_SSL_CERTFILE
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"
If unspecified, the default
timeoutwill be the one provided bysocket.getdefaulttimeout(), which defaults toNone(no timeout).
Console backend¶
Instead of sending out real emails the console backend just writes the
emails that would be sent 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.
File backend¶
The file backend writes emails 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 EMAIL_FILE_PATH setting or from the
file_path keyword when creating a connection with 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.
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 EmailMessage instance for each
message that would be sent.
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.
Django’s test runner automatically uses this backend for testing.
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.
Defining a custom email backend¶
If you need to change how emails are sent you can write your own email
backend. The EMAIL_BACKEND setting in your settings file is then
the Python import path for your backend class.
Custom email backends should subclass BaseEmailBackend that is located in
the django.core.mail.backends.base module. A custom email backend must
implement the send_messages(email_messages) method. This method receives a
list of 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.
Sending multiple emails¶
Establishing and closing an SMTP connection (or any other network connection, for that matter) is an expensive process. If you have a lot of emails to send, it makes sense to reuse an SMTP connection, rather than creating and destroying a connection every time you want to send an email.
There are two ways you tell an email backend to reuse a connection.
Firstly, you can use the send_messages() method on a connection. This takes
a list of EmailMessage (or subclass) instances, and sends them all
using that single connection. As a consequence, any connection set on an individual message is ignored.
For example, if you have a function called get_notification_email() that
returns a list of EmailMessage objects representing some periodic
email you wish to send out, you could send these emails using a single call to
send_messages():
from django.core import mail
connection = mail.get_connection() # Use default email connection
messages = get_notification_email()
connection.send_messages(messages)
In this example, the call to send_messages() opens a connection on the
backend, sends the list of messages, and then closes the connection again.
The second approach is to use the open() and close() methods on the
email backend to manually control the connection. send_messages() will not
manually open or close the connection if it is already open, so if you
manually open the connection, you can control when it is closed. For example:
from django.core import mail
connection = mail.get_connection()
# Manually open the connection
connection.open()
# Construct an email message that uses the connection
email1 = mail.EmailMessage(
"Hello",
"Body goes here",
"from@example.com",
["to1@example.com"],
connection=connection,
)
email1.send() # Send the email
# Construct two more messages
email2 = mail.EmailMessage(
"Hello",
"Body goes here",
"from@example.com",
["to2@example.com"],
)
email3 = mail.EmailMessage(
"Hello",
"Body goes here",
"from@example.com",
["to3@example.com"],
)
# Send the two emails in a single call -
connection.send_messages([email2, email3])
# The connection was already open so send_messages() doesn't close it.
# We need to manually close the connection.
connection.close()
Configuring email for development¶
There are times when you do not want Django to send emails at all. For example, while developing a website, you probably don’t want to send out thousands of emails – but you may want to validate that emails will be sent to the right people under the right conditions, and that those emails will contain the correct content.
The easiest way to configure email for local development is to use the
console email backend. This backend
redirects all email to stdout, allowing you to inspect the content of mail.
The file email backend can also be useful during development – this backend dumps the contents of every SMTP connection to a file that can be inspected at your leisure.
Another approach is to use a “dumb” SMTP server that receives the emails locally and displays them to the terminal, but does not actually send anything. The aiosmtpd package provides a way to accomplish this:
python -m pip install "aiosmtpd >= 1.4.5"
python -m aiosmtpd -n -l localhost:8025
This command will start a minimal SMTP server listening on port 8025 of
localhost. This server prints to standard output all email headers and the
email body. You then only need to set the EMAIL_HOST and
EMAIL_PORT accordingly. For a more detailed discussion of SMTP
server options, see the documentation of the aiosmtpd module.
For information about unit-testing the sending of emails in your application, see the Email services section of the testing documentation.