Enviando e-mailLink para este cabeçalho#

Multiple mailersLink para este cabeçalho#

Sometimes different types of email need to be sent in different ways: e.g., internal vs. external email, different SMTP servers for users in different regions, using different services for transactional notifications and bulk marketing email, etc.

The MAILERS setting can define multiple mail configurations. For example:

import os

MAILERS = {
    "default": {
        "BACKEND": "django.core.mail.backends.smtp.EmailBackend",
        "OPTIONS": {
            "host": "smtp.example.net",
            "use_tls": True,
            "username": os.environ["EMAIL_ACCOUNT_ID"],
            "password": os.environ["EMAIL_API_KEY"],
        },
    },
    "notifications": {
        "BACKEND": "example.third.party.EmailBackend",
        "OPTIONS": {
            "api_key": os.environ["THIRD_PARTY_API_KEY"],
            "region": "eu",
        },
    },
    "admin": {
        "BACKEND": "django.core.mail.backends.smtp.EmailBackend",
        "OPTIONS": {
            "host": "localhost",
        },
    },
}

This defines three mailer configurations:

• "default" sends through an SMTP server at smtp.example.net with a TLS secured connection. It reads an account id and API key from environment variables and uses them as the SMTP authentication username and password. (Many SMTP services use some variation of this authentication scheme.)

• "notifications" sends through a hypothetical commercial email service, using a third-party EmailBackend that connects directly to their API. (See Third-party backends for pointers on locating real, community maintained email backend packages.)

• "admin" sends through an SMTP server running on localhost, with no other options required.

With this configuration, you can provide the using argument to Django’s email sending functions to specify a particular mailer configuration:

from django.core.mail import send_mail

send_mail(
    "Account activated",
    "Congratulations, you're all ready to use our Django app!",
    "from@example.com",
    ["user@example.com"],
    using="notifications",
)

If using is not specified, Django uses the mailer defined for the "default" configuration.

With reusable apps or Django features that send email for you, there may be an option to use a specific mailer configuration. For example, Django’s logging AdminEmailHandler allows specifying the mailer configuration in its using option.

send_mail()Link para este cabeçalho#

send_mail(subject, message, from_email, recipient_list, *, fail_silently=False, auth_user=None, auth_password=None, connection=None, html_message=None)Link para esta definição#

django.core.mail.send_mail() sends a single email message.

Os parâmetros subject, message, from_email e recipient_list devem ser informados.

• subject: uma string.

• message: uma string.

• from_email: A string. If None, Django will use the value of the DEFAULT_FROM_EMAIL setting.

• recipient_list: uma lista de strings, onde cada item representa um endereço de email. Cada membro de recipient_list verá os outros recipientes no campo “To:” da mensagem de email.

The following parameters are optional, and must be given as keyword arguments if used.

• fail_silently: A boolean, default False. If set True, send_mail() will suppress some errors during sending. (The exact exceptions ignored depend on the email backend in use.)

• auth_user: O username opcional para ser usado na autenticação do servidor SMTP. Se isso não for fornecido, o Django irá usar o valor da configuração EMAIL_HOST_USER.

• auth_password: A senha opcional para ser usada na autenticação no servidor SMTP. Se isso não for fornecido, o Django irá usar o valor da configuração EMAIL_HOST_PASSWORD.

• connection: O backend opcional a ser usado para o de email. Se indefinido, uma instância do backend default será usada. Veja a documentação em Email backends para mais detalhes.

• html_message: Se html_message for fornecido, o email resultante será um multipart/alternative email com message sendo do tipo text/plain e html_message sendo do tipo text/html.

• using: An optional MAILERS alias to use to send the mail. If unspecified, the default mailer configuration will be used.

fail_silently, auth_user, auth_password, and connection are not allowed with the using argument.

O valor retornado será o número de mensagens entregues com sucesso (o que pode ser 0 ou 1 já que ele só pode enviar uma mensagem).

send_mass_mail()Link para este cabeçalho#

send_mass_mail(datatuple, *, fail_silently=False, auth_user=None, auth_password=None, connection=None, using=None)Link para esta definição#

django.core.mail.send_mass_mail() foi pensado para manipular envios massivos de email.

datatuple é uma tupla na qual cada elemento possui o seguinte formato:

(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, and are not allowed with the using argument.

The keyword argument using is an optional MAILERS alias to use to send the mail. If unspecified, the default mailer configuration will be 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.

Por exemplo, o código abaixo enviaria duas mensagens diferentes para dois conjuntos diferentes de destinatários; porém, somente uma conexão para o servidor de email seria aberta:

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))

O valor de retorno será o número de mensagens entregues com sucesso.

send_mail(
    "Subject",
    "Message.",
    "from@example.com",
    ["john@example.com", "jane@example.com"],
)

datatuple = (
    ("Subject", "Message.", "from@example.com", ["john@example.com"]),
    ("Subject", "Message.", "from@example.com", ["jane@example.com"]),
)
send_mass_mail(datatuple)

mail_admins()Link para este cabeçalho#

mail_admins(subject, message, *, fail_silently=False, connection=None, html_message=None, using=None)Link para esta definição#

django.core.mail.mail_admins() é um atalho para o envio de email para os admins do site, conforme definido na configuração ADMINS setting.

mail_admins() prefixa o conteúdo com o valor da configuração EMAIL_SUBJECT_PREFIX, que é "[Django] " por padrão.

O cabeçalho “From:” do email será o valor da configuração SERVER_EMAIL.

Esse método existe por conveniência e legibilidade.

Se html_message é fornecido, o email resultante será um email do tipo multipart/alternative com message sendo do tipo text/plain e html_message sendo do tipo text/html.

The keyword argument using is an optional MAILERS alias to use to send the mail. If unspecified, the default mailer configuration will be used.

mail_managers()Link para este cabeçalho#

mail_managers(subject, message, *, fail_silently=False, connection=None, html_message=None, using=None)Link para esta definição#

django.core.mail.mail_managers() é parecido com mail_admins(), exceto pelo fato de que ele envia um email para os mantenedores do site, conforme definido na configuração MANAGERS.

The keyword argument using is an optional MAILERS alias to use to send the mail. If unspecified, the default mailer configuration will be used.

A classe EmailMessageLink para este cabeçalho#

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.

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.

class EmailMessageLink para esta definição#

The EmailMessage class is initialized with the following parameters. All parameters are optional and can be set at any time prior to calling the send() 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: A linha de assunto do email.

• body: O corpo do texto. Deve ser uma mensagem em texto simples.

• from_email: The sender’s address. Both fred@example.com and "Fred" <fred@example.com> forms are supported (see Formatting email addresses). If omitted, the DEFAULT_FROM_EMAIL setting is used.

• to: Uma lista de tuplas de endereços dos destinatários.

The following parameters must be given as keyword arguments if used:

• cc: uma lista ou tupla de endereços de destinatários usados no cabeçalho “Cc” no envio do email.

• bcc: A list or tuple of addresses used for blind carbon copies when sending the email.

• reply_to: uma lista ou tupla de endereços de destinatários usados no cabeçalho “Reply-To” no envio do email.

• attachments: A list of attachments to put on the message. Each can be an instance of MIMEPart or EmailAttachment, or a tuple with attributes (filename, content, mimetype).

• headers: um dicionário de cabeçalhos extras para colocar na mensagem. As chaves são os nomes dos cabeçalhos, valores são os valores do cabeçalho. É responsabilidade de quem chama garantir que os nomes e valores dos cabeçalhos estão no formato correto para uma mensagem de email. O atributo correspondente é extra_headers.

• connection: An email backend instance. This parameter is ignored when using send_messages().

Por exemplo:

Code

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"},
)

A classe possui os seguintes métodos:

send(fail_silently=False, *, using=None)Link para esta definição#

Sends the message. Returns 1 if the message was sent successfully, otherwise 0. (An empty list of recipients returns 0 – it will not raise an exception.)

The optional using keyword argument specifies a MAILERS alias to use to send the mail. If not given, the default mailer configuration will be used.

If a deprecated connection was specified when the email was constructed, that connection will be used. Providing both a connection and using will raise an error.

If the deprecated keyword argument fail_silently is True, certain backend-dependent exceptions while sending the message will be ignored. Providing both fail_silently and using will raise an error.

message(*, policy=email.policy.default)Link para esta definição#

Constructs and returns a Python email.message.EmailMessage object representing the message to be sent.

The keyword argument policy allows specifying the set of rules for updating and serializing the representation of the message. It must be an email.policy.Policy object. Defaults to email.policy.default. In certain cases you may want to use SMTP, SMTPUTF8 or a custom policy. For example, the SMTP email backend uses the SMTP policy to ensure \r\n line endings as required by the SMTP protocol.

If you ever need to extend Django’s EmailMessage class, you’ll probably want to override this method to put the content you want into the Python EmailMessage object.

recipients()Link para esta definição#

Returns a list of all the recipients of the message, whether they’re recorded in the to, cc 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(filename, content, mimetype)Link para esta definição#

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, 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.

  Por exemplo:

  Code

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

  If you specify a mimetype of message/rfc822, content can be a django.core.mail.EmailMessage or Python’s email.message.EmailMessage or email.message.Message.

  For a mimetype starting 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 Python MIMEPart object. This will be attached directly to the resulting message. For example, to attach an inline image with a Content-ID:

  Code

  import email.utils
  from email.message import MIMEPart
  from django.core.mail import EmailMultiAlternatives
  
  message = EmailMultiAlternatives(...)
  image_data_bytes = ...  # Load image as bytes
  
  # Create a random Content-ID, including angle brackets
  cid = email.utils.make_msgid()
  inline_image = email.message.MIMEPart()
  inline_image.set_content(
      image_data_bytes,
      maintype="image",
      subtype="png",  # or "jpeg", etc. depending on the image type
      disposition="inline",
      cid=cid,
  )
  message.attach(inline_image)
  # Refer to Content-ID in HTML without angle brackets
  message.attach_alternative(f'… <img src="cid:{cid[1:-1]}"> …', "text/html")
  

  Python’s email.contentmanager.set_content() documentation describes the supported arguments for MIMEPart.set_content().

attach_file(path, mimetype=None)Link para esta definição#

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:

Code

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

For MIME types starting with text/, binary data is handled as in attach().

class EmailAttachmentLink para esta definição#

A named tuple to store attachments to an email.

The named tuple has the following indexes:

• filename

• content

• mimetype

msg = EmailMessage(subject, html_content, from_email, [to])
msg.content_subtype = "html"  # Main content is now text/html
msg.send()

Safely sending emailLink para este cabeçalho#

Any public website that can send email will eventually be targeted by attempts to abuse it for spam, phishing, or other malicious content. While a complete discussion of vulnerabilities in sending email is beyond the scope of Django’s documentation, there are many references available on the web. Two good starting points are:

• Princeton University’s guidance on preventing email abuse in web forms. Although this is an internal reference for users of Princeton’s Drupal Site Builder, nearly all of its advice applies equally to sites built with Django (or any web framework).

• OWASP’s Email Validation and Verification in Identity Systems Cheat Sheet. This primarily covers using email in authentication contexts. While many of its recommendations are handled by django.contrib.auth and other Django features, items like rate limiting and securing email change workflows are the developer’s responsibility.

Thinking through how email might be abused (and taking steps to mitigate it) is especially important if your site can send to unverified addresses. Features like newsletter sign-up, contact forms that cc or auto-reply to the sender, and “share this page” can be attractive targets.

DEFAULT_FROM_EMAIL = '"Example, Inc." <contact@example.com>'

from django.core.mail import send_mail
from email.headerregistry import Address


def send_mail_to_user(user, subject, body, from_email=None):
    # Safely create an email address with the user's name.
    # (addr_spec is the technical term for the user@domain address.)
    address = Address(
        display_name=user.get_full_name(),
        addr_spec=user.email,
    )
    send_mail(subject, body, from_email, [address])

Sending many messages efficientlyLink para este cabeçalho#

Estabelecer e fechar uma conexão SMTP (ou qualquer outra conexão de rede, nesse caso) é um processo custoso. Se você tem muitos emails para enviar, faz sentido reutilizar uma conexão SMTP, ao invés de criar e destruir uma conexão toda vez que você desejar enviar um email.

There are two ways to tell an email backend to reuse a connection. Both involve obtaining an email backend instance from mail.mailers and using the backend’s API.

The first approach is to use the backend’s send_messages() method. This takes a list of EmailMessage (or subclass) instances, and sends them all using that single connection.

For example, if you have a function called get_notification_emails() 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

email_list = get_notification_emails()
# Use the default mailer. You could substitute
# mail.mailers["alias"] for a specific mailer.
backend = mail.mailers.default
backend.send_messages(email_list)

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. (This is how send_mass_mail() is implemented.)

The second approach is to use the open() and close() methods on the email backend to manually control the connection. send_messages() will not 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

# Use the "notifications" mailer configuration.
backend = mail.mailers["notifications"]

# Manually open the connection.
backend.open()

# Construct an email message. (Passing None as the third argument
# uses settings.DEFAULT_FROM_EMAIL as the "From:" address.)
email1 = mail.EmailMessage("Hi", "Message", None, ["to1@example.com"])
# Send the email. The connection was already open, so send_messages()
# leaves it open after sending.
backend.send_messages([email1])

# Construct and send two more messages. The connection is still open.
email2 = mail.EmailMessage("Hi", "Message", None, ["to2@example.com"])
email3 = mail.EmailMessage("Hi", "Message", None, ["to3@example.com"])
backend.send_messages([email2, email3])

# Because we opened it, we need to manually close the connection.
backend.close()

When you manually open a backend’s connection, you are responsible for ensuring it gets closed. The example above actually has a bug: if an exception occurs while sending the messages, the connection will not be closed. This can be fixed with a try-finally statement, but using the backend instance as a context manager is preferable, as it automatically calls open() and close() as needed.

This is equivalent to the previous example, but uses the backend as a context manager to avoid leaving the connection open on errors:

from django.core import mail

# Use mail.mailers[...] as a context manager.
with mail.mailers["notifications"] as backend:
    # The backend connection is automatically opened inside the context.
    email1 = mail.EmailMessage("Hi", "Message", None, ["to1@example.com"])
    backend.send_messages([email1])

    # The connection is still open, and is reused for the second send.
    email2 = mail.EmailMessage("Hi", "Message", None, ["to2@example.com"])
    email3 = mail.EmailMessage("Hi", "Message", None, ["to3@example.com"])
    backend.send_messages([email2, email3])

# After exiting the context (either normally or because of an error),
# the backend connection is automatically closed.

SMTP backendLink para este cabeçalho#

The SMTP email backend connects to an SMTP server to send email. To use it, set BACKEND to "django.core.mail.backends.smtp.EmailBackend".

The SMTP backend supports these OPTIONS:

• "host" (required): the SMTP server hostname or IP address.

• "port": the port number to connect to on the SMTP host. If omitted, uses the standard port for the connection protocol depending on the "use_tls" and "use_ssl" options: 587 for TLS, 465 for SSL, or 25 for an unsecured connection.

• "username" and "password": set these if your server requires SMTP authentication (“SMTP AUTH” credentials, sometimes called SMTP login).

  Although the username is often an email address, it should not be confused with default “From:” addresses. Those are defined by the DEFAULT_FROM_EMAIL and SERVER_EMAIL settings.

• "use_tls" or "use_ssl": set one of these options to True to connect to the SMTP server using a secure protocol – "use_tls" for explicit TLS or "use_ssl" for SSL (implicit TLS).

• "ssl_certfile" and "ssl_keyfile": if the SMTP server’s SSL/TLS connection requires client certificate authentication, use these options to specify the paths to a PEM-formatted certificate chain file and private key file. (The key file can be omitted if the certificate file includes the private key.)

  These options are not intended for use with a private certificate authority or self-signed SMTP server certificate. See Private and self-signed SMTP server certificates below.

  Note that these options don’t result in checking certificate validity. They are passed to the underlying SSL connection. Refer to the documentation of Python’s ssl.SSLContext.wrap_socket() method for details on how the certificate chain file and private key file are handled.

• "timeout": the timeout (in seconds) for connecting to the SMTP server and other blocking operations. If not specified, the value is obtained from socket.getdefaulttimeout(), which defaults to no timeout (None) meaning SMTP operations can block indefinitely.

• "fail_silently": set to True to ignore certain errors while sending a message. All OSErrors are ignored while opening the SMTP connection, and smtplib.SMTPException errors are ignored while communicating with the server. This will suppress both transient network glitches and also serious configuration problems. However, it does not ignore all errors, and problems with serializing the message will not fail silently. (This option is available for backward compatibility but is not recommended for typical use.)

Exemplo

MAILERS = {
    "default": {
        "BACKEND": "django.core.mail.backends.smtp.EmailBackend",
        "OPTIONS": {
            "host": "smtp.example.net",
            "use_tls": True,
            "username": "my-app",
            "password": os.environ["MY_APP_SMTP_PASSWORD"],
            "timeout": 10,
        },
    },
}

class backends.smtp.EmailBackendLink para esta definição#

Directly instantiating an EmailBackend class is not recommended. Use mailers to obtain a backend instance.

When constructed directly (without going through mailers), the SMTP EmailBackend class accepts the options listed above as keyword arguments. Default values come from the corresponding, deprecated EMAIL_* settings. host is not required and defaults to "localhost", and port defaults to 25 even if use_tls or use_ssl is True.

When the MAILERS setting is defined, attempting to directly create an SMTP EmailBackend will raise an AttributeError.

Console backendLink para este cabeçalho#

Instead of sending out real emails, the console backend writes the emails that would be sent to the standard output. To use it, set BACKEND to "django.core.mail.backends.console.EmailBackend".

The console backend supports these OPTIONS:

• "stream": a stream-like object to write to. Defaults to stdout.

• "fail_silently": set to True to ignore all errors while writing the message to the stream, including errors serializing the message. (This option is available for backward compatibility but is not recommended.)

Esse backend não é intencionado para uso em produção – ele é fornecido como uma conveniência que pode ser usado durante o desenvolvimento.

File backendLink para este cabeçalho#

The file backend writes emails to a file. A new file is created for each new session that is opened on this backend. To use it, set BACKEND to "django.core.mail.backends.filebased.EmailBackend".

The file backend supports these OPTIONS:

• "file_path" (required): the directory to which the files are written. Can be a string or a pathlib.Path object. If the directory does not exist, the file backend will attempt to create it.

• "fail_silently": set to True to ignore all errors while writing the message to the file – including errors serializing the message – but not errors related to ensuring the file path directory exists. (This option is available for backward compatibility but is not recommended.)

Esse backend não é intencionado para uso em produção – ele é fornecido como uma conveniência que pode ser usado durante o desenvolvimento.

In-memory backendLink para este cabeçalho#

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. Messages in the outbox are annotated with a sent_using attribute that identifies the MAILERS alias used to send the message.

To use the in-memory backend, set BACKEND to "django.core.mail.backends.locmem.EmailBackend". It does not support any OPTIONS.

Django’s test runner automatically switches to this backend for testing.

Esse backend não é intencionado para uso em produção – ele é fornecido como uma conveniência que pode ser usado durante o desenvolvimento e teste.

Dummy backendLink para este cabeçalho#

As the name suggests the dummy backend does nothing with your messages. To use it, set BACKEND to "django.core.mail.backends.dummy.EmailBackend". It does not support any OPTIONS.

Esse backend não é intencionado para uso em produção – ele é fornecido como uma conveniência que pode ser usado durante o desenvolvimento.

Third-party backendsLink para este cabeçalho#

Third-party email backends are available that:

• Integrate directly with commercial email service providers’ APIs (which often have extra functionality not available through SMTP).

• Offload email sending to asynchronous task queues.

• Add features to other email backends, such as enforcing do-not-send lists or logging sent messages.

• Provide development and debugging tools, such as sandbox capture and in-browser email previews.

Definindo um email backend customizadoLink para este cabeçalho#

If you need to change how emails are sent you can write your own email backend. To use a custom backend, set BACKEND to the Python import path for your backend class and OPTIONS to any __init__() keyword arguments your backend supports.

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.

Obtendo uma instância de um email backendLink para este cabeçalho#

The mailers factory in django.core.mail returns instances of email backends.

mailersLink para esta definição#

You can access the mailers configured in the MAILERS setting through a dict-like object: django.core.mail.mailers:

Python console

>>> from django.core.mail import mailers
>>> mailers["notifications"]

If the named key is not defined, a MailerDoesNotExist error will be raised. Other configuration problems will raise an InvalidMailer error.

mailers.defaultLink para esta definição#

As a shortcut, the default mailer can be accessed through django.core.mail.mailers.default:

Python console

>>> from django.core.mail import mailers
>>> mailers.default

This is equivalent to mailers["default"]. If no default mailer has been configured, a MailerDoesNotExist error will be raised.

get_connection(backend=None, *, fail_silently=False, **kwargs)Link para esta definição#

The deprecated django.core.mail.get_connection() function creates and returns an instance of an email backend. Its behavior depends on the MAILERS setting and how the function is called.

If the MAILERS setting is defined:

• get_connection() with no arguments will return mailers.default.

• get_connection(...) called with only fail_silently or other keyword arguments will create an instance of MAILERS["default"] with any keywords added to the default mailer’s OPTIONS.

• get_connection(backend, ...) with a backend import path will raise an error.

If the MAILERS setting is not defined:

• get_connection() with no arguments 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.

• If the keyword argument fail_silently is True, certain backend-dependent exceptions during the email sending process will be silently ignored.

• All other keyword arguments are passed directly to the constructor of the email backend.

Email backend APILink para este cabeçalho#

Instances of an email backend class have the following methods:

• open() instancia uma conexão de longa duração para envio de email.

• close() fecha a conexão atual de envio de email.

• send_messages(email_messages) sends a list of EmailMessage objects. 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.

A backend instance can also be used as a context manager, which will automatically call open() and close() as needed. An example is in Sending many messages efficiently.