import asyncore
import base64
import mimetypes
import os
import shutil
import smtpd
import socket
import sys
import tempfile
import threading
from email import message_from_binary_file, message_from_bytes
from email.header import Header
from email.mime.text import MIMEText
from email.utils import parseaddr
from smtplib import SMTP, SMTPAuthenticationError, SMTPException
from ssl import SSLError

from django.core import mail
from django.core.mail import (
    EmailMessage, EmailMultiAlternatives, mail_admins, mail_managers,
    send_mail, send_mass_mail,
)
from django.core.mail.backends import console, dummy, filebased, locmem, smtp
from django.core.mail.message import BadHeaderError, sanitize_address
from django.test import SimpleTestCase, override_settings
from django.test.utils import requires_tz_support
from django.utils._os import upath
from django.utils.encoding import force_bytes, force_text
from django.utils.six import StringIO
from django.utils.translation import ugettext_lazy


class HeadersCheckMixin(object):

    def assertMessageHasHeaders(self, message, headers):
        """
        Asserts that the `message` has all `headers`.

        message: can be an instance of an email.Message subclass or a string
                 with the contents of an email message.
        headers: should be a set of (header-name, header-value) tuples.
        """
        if isinstance(message, bytes):
            message = message_from_bytes(message)
        msg_headers = set(message.items())
        self.assertTrue(headers.issubset(msg_headers), msg='Message is missing '
                        'the following headers: %s' % (headers - msg_headers),)


class MailTests(HeadersCheckMixin, SimpleTestCase):
    """
    Non-backend specific tests.
    """
    def get_decoded_attachments(self, django_message):
        """
        Encode the specified django.core.mail.message.EmailMessage, then decode
        it using Python's email.parser module and, for each attachment of the
        message, return a list of tuples with (filename, content, mimetype).
        """
        msg_bytes = django_message.message().as_bytes()
        email_message = message_from_bytes(msg_bytes)

        def iter_attachments():
            for i in email_message.walk():
                # Once support for Python<3.5 has been dropped, we can use
                # i.get_content_disposition() here instead.
                content_disposition = i.get('content-disposition', '').split(';')[0].lower()
                if content_disposition == 'attachment':
                    filename = i.get_filename()
                    content = i.get_payload(decode=True)
                    mimetype = i.get_content_type()
                    yield filename, content, mimetype

        return list(iter_attachments())

    def test_ascii(self):
        email = EmailMessage('Subject', 'Content', 'from@example.com', ['to@example.com'])
        message = email.message()
        self.assertEqual(message['Subject'], 'Subject')
        self.assertEqual(message.get_payload(), 'Content')
        self.assertEqual(message['From'], 'from@example.com')
        self.assertEqual(message['To'], 'to@example.com')

    def test_multiple_recipients(self):
        email = EmailMessage('Subject', 'Content', 'from@example.com', ['to@example.com', 'other@example.com'])
        message = email.message()
        self.assertEqual(message['Subject'], 'Subject')
        self.assertEqual(message.get_payload(), 'Content')
        self.assertEqual(message['From'], 'from@example.com')
        self.assertEqual(message['To'], 'to@example.com, other@example.com')

    def test_recipients_with_empty_strings(self):
        """
        Empty strings in various recipient arguments are always stripped
        off the final recipient list.
        """
        email = EmailMessage(
            'Subject', 'Content', 'from@example.com', ['to@example.com', ''],
            cc=['cc@example.com', ''],
            bcc=['', 'bcc@example.com'],
            reply_to=['', None],
        )
        self.assertEqual(
            email.recipients(),
            ['to@example.com', 'cc@example.com', 'bcc@example.com']
        )

    def test_cc(self):
        """Regression test for #7722"""
        email = EmailMessage('Subject', 'Content', 'from@example.com', ['to@example.com'], cc=['cc@example.com'])
        message = email.message()
        self.assertEqual(message['Cc'], 'cc@example.com')
        self.assertEqual(email.recipients(), ['to@example.com', 'cc@example.com'])

        # Test multiple CC with multiple To
        email = EmailMessage(
            'Subject', 'Content', 'from@example.com', ['to@example.com', 'other@example.com'],
            cc=['cc@example.com', 'cc.other@example.com']
        )
        message = email.message()
        self.assertEqual(message['Cc'], 'cc@example.com, cc.other@example.com')
        self.assertEqual(
            email.recipients(),
            ['to@example.com', 'other@example.com', 'cc@example.com', 'cc.other@example.com']
        )

        # Testing with Bcc
        email = EmailMessage(
            'Subject', 'Content', 'from@example.com', ['to@example.com', 'other@example.com'],
            cc=['cc@example.com', 'cc.other@example.com'], bcc=['bcc@example.com']
        )
        message = email.message()
        self.assertEqual(message['Cc'], 'cc@example.com, cc.other@example.com')
        self.assertEqual(
            email.recipients(),
            ['to@example.com', 'other@example.com', 'cc@example.com', 'cc.other@example.com', 'bcc@example.com']
        )

    def test_reply_to(self):
        email = EmailMessage(
            'Subject', 'Content', 'from@example.com', ['to@example.com'],
            reply_to=['reply_to@example.com'],
        )
        message = email.message()
        self.assertEqual(message['Reply-To'], 'reply_to@example.com')

        email = EmailMessage(
            'Subject', 'Content', 'from@example.com', ['to@example.com'],
            reply_to=['reply_to1@example.com', 'reply_to2@example.com']
        )
        message = email.message()
        self.assertEqual(message['Reply-To'], 'reply_to1@example.com, reply_to2@example.com')

    def test_recipients_as_tuple(self):
        email = EmailMessage(
            'Subject', 'Content', 'from@example.com', ('to@example.com', 'other@example.com'),
            cc=('cc@example.com', 'cc.other@example.com'), bcc=('bcc@example.com',)
        )
        message = email.message()
        self.assertEqual(message['Cc'], 'cc@example.com, cc.other@example.com')
        self.assertEqual(
            email.recipients(),
            ['to@example.com', 'other@example.com', 'cc@example.com', 'cc.other@example.com', 'bcc@example.com']
        )

    def test_recipients_as_string(self):
        with self.assertRaisesMessage(TypeError, '"to" argument must be a list or tuple'):
            EmailMessage(to='foo@example.com')
        with self.assertRaisesMessage(TypeError, '"cc" argument must be a list or tuple'):
            EmailMessage(cc='foo@example.com')
        with self.assertRaisesMessage(TypeError, '"bcc" argument must be a list or tuple'):
            EmailMessage(bcc='foo@example.com')
        with self.assertRaisesMessage(TypeError, '"reply_to" argument must be a list or tuple'):
            EmailMessage(reply_to='reply_to@example.com')

    def test_header_injection(self):
        email = EmailMessage('Subject\nInjection Test', 'Content', 'from@example.com', ['to@example.com'])
        with self.assertRaises(BadHeaderError):
            email.message()
        email = EmailMessage(
            ugettext_lazy('Subject\nInjection Test'), 'Content', 'from@example.com', ['to@example.com']
        )
        with self.assertRaises(BadHeaderError):
            email.message()

    def test_space_continuation(self):
        """
        Test for space continuation character in long (ASCII) subject headers (#7747)
        """
        email = EmailMessage(
            'Long subject lines that get wrapped should contain a space '
            'continuation character to get expected behavior in Outlook and Thunderbird',
            'Content', 'from@example.com', ['to@example.com']
        )
        message = email.message()
        # Note that in Python 3, maximum line length has increased from 76 to 78
        self.assertEqual(
            message['Subject'].encode(),
            b'Long subject lines that get wrapped should contain a space continuation\n'
            b' character to get expected behavior in Outlook and Thunderbird'
        )

    def test_message_header_overrides(self):
        """
        Specifying dates or message-ids in the extra headers overrides the
        default values (#9233)
        """
        headers = {"date": "Fri, 09 Nov 2001 01:08:47 -0000", "Message-ID": "foo"}
        email = EmailMessage('subject', 'content', 'from@example.com', ['to@example.com'], headers=headers)

        self.assertMessageHasHeaders(email.message(), {
            ('Content-Transfer-Encoding', '7bit'),
            ('Content-Type', 'text/plain; charset="utf-8"'),
            ('From', 'from@example.com'),
            ('MIME-Version', '1.0'),
            ('Message-ID', 'foo'),
            ('Subject', 'subject'),
            ('To', 'to@example.com'),
            ('date', 'Fri, 09 Nov 2001 01:08:47 -0000'),
        })

    def test_from_header(self):
        """
        Make sure we can manually set the From header (#9214)
        """
        email = EmailMessage(
            'Subject', 'Content', 'bounce@example.com', ['to@example.com'],
            headers={'From': 'from@example.com'},
        )
        message = email.message()
        self.assertEqual(message['From'], 'from@example.com')

    def test_to_header(self):
        """
        Make sure we can manually set the To header (#17444)
        """
        email = EmailMessage('Subject', 'Content', 'bounce@example.com',
                             ['list-subscriber@example.com', 'list-subscriber2@example.com'],
                             headers={'To': 'mailing-list@example.com'})
        message = email.message()
        self.assertEqual(message['To'], 'mailing-list@example.com')
        self.assertEqual(email.to, ['list-subscriber@example.com', 'list-subscriber2@example.com'])

        # If we don't set the To header manually, it should default to the `to` argument to the constructor
        email = EmailMessage('Subject', 'Content', 'bounce@example.com',
                             ['list-subscriber@example.com', 'list-subscriber2@example.com'])
        message = email.message()
        self.assertEqual(message['To'], 'list-subscriber@example.com, list-subscriber2@example.com')
        self.assertEqual(email.to, ['list-subscriber@example.com', 'list-subscriber2@example.com'])

    def test_reply_to_header(self):
        """
        Specifying 'Reply-To' in headers should override reply_to.
        """
        email = EmailMessage(
            'Subject', 'Content', 'bounce@example.com', ['to@example.com'],
            reply_to=['foo@example.com'], headers={'Reply-To': 'override@example.com'},
        )
        message = email.message()
        self.assertEqual(message['Reply-To'], 'override@example.com')

    def test_multiple_message_call(self):
        """
        Regression for #13259 - Make sure that headers are not changed when
        calling EmailMessage.message()
        """
        email = EmailMessage(
            'Subject', 'Content', 'bounce@example.com', ['to@example.com'],
            headers={'From': 'from@example.com'},
        )
        message = email.message()
        self.assertEqual(message['From'], 'from@example.com')
        message = email.message()
        self.assertEqual(message['From'], 'from@example.com')

    def test_unicode_address_header(self):
        """
        Regression for #11144 - When a to/from/cc header contains unicode,
        make sure the email addresses are parsed correctly (especially with
        regards to commas)
        """
        email = EmailMessage(
            'Subject', 'Content', 'from@example.com',
            ['"Firstname Sürname" <to@example.com>', 'other@example.com'],
        )
        self.assertEqual(
            email.message()['To'],
            '=?utf-8?q?Firstname_S=C3=BCrname?= <to@example.com>, other@example.com'
        )
        email = EmailMessage(
            'Subject', 'Content', 'from@example.com',
            ['"Sürname, Firstname" <to@example.com>', 'other@example.com'],
        )
        self.assertEqual(
            email.message()['To'],
            '=?utf-8?q?S=C3=BCrname=2C_Firstname?= <to@example.com>, other@example.com'
        )

    def test_unicode_headers(self):
        email = EmailMessage("Gżegżółka", "Content", "from@example.com", ["to@example.com"],
                             headers={"Sender": '"Firstname Sürname" <sender@example.com>',
                                      "Comments": 'My Sürname is non-ASCII'})
        message = email.message()
        self.assertEqual(message['Subject'], '=?utf-8?b?R8W8ZWfFvMOzxYJrYQ==?=')
        self.assertEqual(message['Sender'], '=?utf-8?q?Firstname_S=C3=BCrname?= <sender@example.com>')
        self.assertEqual(message['Comments'], '=?utf-8?q?My_S=C3=BCrname_is_non-ASCII?=')

    def test_safe_mime_multipart(self):
        """
        Make sure headers can be set with a different encoding than utf-8 in
        SafeMIMEMultipart as well
        """
        headers = {"Date": "Fri, 09 Nov 2001 01:08:47 -0000", "Message-ID": "foo"}
        from_email, to = 'from@example.com', '"Sürname, Firstname" <to@example.com>'
        text_content = 'This is an important message.'
        html_content = '<p>This is an <strong>important</strong> message.</p>'
        msg = EmailMultiAlternatives('Message from Firstname Sürname', text_content, from_email, [to], headers=headers)
        msg.attach_alternative(html_content, "text/html")
        msg.encoding = 'iso-8859-1'
        self.assertEqual(msg.message()['To'], '=?iso-8859-1?q?S=FCrname=2C_Firstname?= <to@example.com>')
        self.assertEqual(msg.message()['Subject'], '=?iso-8859-1?q?Message_from_Firstname_S=FCrname?=')

    def test_encoding(self):
        """
        Regression for #12791 - Encode body correctly with other encodings
        than utf-8
        """
        email = EmailMessage('Subject', 'Firstname Sürname is a great guy.', 'from@example.com', ['other@example.com'])
        email.encoding = 'iso-8859-1'
        message = email.message()
        self.assertMessageHasHeaders(message, {
            ('MIME-Version', '1.0'),
            ('Content-Type', 'text/plain; charset="iso-8859-1"'),
            ('Content-Transfer-Encoding', 'quoted-printable'),
            ('Subject', 'Subject'),
            ('From', 'from@example.com'),
            ('To', 'other@example.com')})
        self.assertEqual(message.get_payload(), 'Firstname S=FCrname is a great guy.')

        # Make sure MIME attachments also works correctly with other encodings than utf-8
        text_content = 'Firstname Sürname is a great guy.'
        html_content = '<p>Firstname Sürname is a <strong>great</strong> guy.</p>'
        msg = EmailMultiAlternatives('Subject', text_content, 'from@example.com', ['to@example.com'])
        msg.encoding = 'iso-8859-1'
        msg.attach_alternative(html_content, "text/html")
        payload0 = msg.message().get_payload(0)
        self.assertMessageHasHeaders(payload0, {
            ('MIME-Version', '1.0'),
            ('Content-Type', 'text/plain; charset="iso-8859-1"'),
            ('Content-Transfer-Encoding', 'quoted-printable')})
        self.assertTrue(payload0.as_bytes().endswith(b'\n\nFirstname S=FCrname is a great guy.'))
        payload1 = msg.message().get_payload(1)
        self.assertMessageHasHeaders(payload1, {
            ('MIME-Version', '1.0'),
            ('Content-Type', 'text/html; charset="iso-8859-1"'),
            ('Content-Transfer-Encoding', 'quoted-printable')})
        self.assertTrue(
            payload1.as_bytes().endswith(b'\n\n<p>Firstname S=FCrname is a <strong>great</strong> guy.</p>')
        )

    def test_attachments(self):
        """Regression test for #9367"""
        headers = {"Date": "Fri, 09 Nov 2001 01:08:47 -0000", "Message-ID": "foo"}
        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], headers=headers)
        msg.attach_alternative(html_content, "text/html")
        msg.attach("an attachment.pdf", b"%PDF-1.4.%...", mimetype="application/pdf")
        msg_bytes = msg.message().as_bytes()
        message = message_from_bytes(msg_bytes)
        self.assertTrue(message.is_multipart())
        self.assertEqual(message.get_content_type(), 'multipart/mixed')
        self.assertEqual(message.get_default_type(), 'text/plain')
        payload = message.get_payload()
        self.assertEqual(payload[0].get_content_type(), 'multipart/alternative')
        self.assertEqual(payload[1].get_content_type(), 'application/pdf')

    def test_non_ascii_attachment_filename(self):
        """Regression test for #14964"""
        headers = {"Date": "Fri, 09 Nov 2001 01:08:47 -0000", "Message-ID": "foo"}
        subject, from_email, to = 'hello', 'from@example.com', 'to@example.com'
        content = 'This is the message.'
        msg = EmailMessage(subject, content, from_email, [to], headers=headers)
        # Unicode in file name
        msg.attach("une pièce jointe.pdf", b"%PDF-1.4.%...", mimetype="application/pdf")
        msg_bytes = msg.message().as_bytes()
        message = message_from_bytes(msg_bytes)
        payload = message.get_payload()
        self.assertEqual(payload[1].get_filename(), 'une pièce jointe.pdf')

    def test_attach_file(self):
        """
        Test attaching a file against different mimetypes and make sure that
        a file will be attached and sent properly even if an invalid mimetype
        is specified.
        """
        files = (
            # filename, actual mimetype
            ('file.txt', 'text/plain'),
            ('file.png', 'image/png'),
            ('file_txt', None),
            ('file_png', None),
            ('file_txt.png', 'image/png'),
            ('file_png.txt', 'text/plain'),
        )
        test_mimetypes = ['text/plain', 'image/png', None]

        for basename, real_mimetype in files:
            for mimetype in test_mimetypes:
                email = EmailMessage('subject', 'body', 'from@example.com', ['to@example.com'])
                self.assertEqual(mimetypes.guess_type(basename)[0], real_mimetype)
                self.assertEqual(email.attachments, [])
                file_path = os.path.join(os.path.dirname(upath(__file__)), 'attachments', basename)
                email.attach_file(file_path, mimetype=mimetype)
                self.assertEqual(len(email.attachments), 1)
                self.assertIn(basename, email.attachments[0])
                msgs_sent_num = email.send()
                self.assertEqual(msgs_sent_num, 1)

    def test_attach_text_as_bytes(self):
        msg = EmailMessage('subject', 'body', 'from@example.com', ['to@example.com'])
        msg.attach('file.txt', b'file content')
        sent_num = msg.send()
        self.assertEqual(sent_num, 1)
        filename, content, mimetype = self.get_decoded_attachments(msg)[0]
        self.assertEqual(filename, 'file.txt')
        self.assertEqual(content, b'file content')
        self.assertEqual(mimetype, 'text/plain')

    def test_attach_utf8_text_as_bytes(self):
        """
        Non-ASCII characters encoded as valid UTF-8 are correctly transported
        and decoded.
        """
        msg = EmailMessage('subject', 'body', 'from@example.com', ['to@example.com'])
        msg.attach('file.txt', b'\xc3\xa4')  # UTF-8 encoded a umlaut.
        filename, content, mimetype = self.get_decoded_attachments(msg)[0]
        self.assertEqual(filename, 'file.txt')
        self.assertEqual(content, b'\xc3\xa4')
        self.assertEqual(mimetype, 'text/plain')

    def test_attach_non_utf8_text_as_bytes(self):
        """
        Binary data that can't be decoded as UTF-8 overrides the MIME type
        instead of decoding the data.
        """
        msg = EmailMessage('subject', 'body', 'from@example.com', ['to@example.com'])
        msg.attach('file.txt', b'\xff')  # Invalid UTF-8.
        filename, content, mimetype = self.get_decoded_attachments(msg)[0]
        self.assertEqual(filename, 'file.txt')
        # Content should be passed through unmodified.
        self.assertEqual(content, b'\xff')
        self.assertEqual(mimetype, 'application/octet-stream')

    def test_dummy_backend(self):
        """
        Make sure that dummy backends returns correct number of sent messages
        """
        connection = dummy.EmailBackend()
        email = EmailMessage(
            'Subject', 'Content', 'bounce@example.com', ['to@example.com'],
            headers={'From': 'from@example.com'},
        )
        self.assertEqual(connection.send_messages([email, email, email]), 3)

    def test_arbitrary_keyword(self):
        """
        Make sure that get_connection() accepts arbitrary keyword that might be
        used with custom backends.
        """
        c = mail.get_connection(fail_silently=True, foo='bar')
        self.assertTrue(c.fail_silently)

    def test_custom_backend(self):
        """Test custom backend defined in this suite."""
        conn = mail.get_connection('mail.custombackend.EmailBackend')
        self.assertTrue(hasattr(conn, 'test_outbox'))
        email = EmailMessage(
            'Subject', 'Content', 'bounce@example.com', ['to@example.com'],
            headers={'From': 'from@example.com'},
        )
        conn.send_messages([email])
        self.assertEqual(len(conn.test_outbox), 1)

    def test_backend_arg(self):
        """Test backend argument of mail.get_connection()"""
        self.assertIsInstance(mail.get_connection('django.core.mail.backends.smtp.EmailBackend'), smtp.EmailBackend)
        self.assertIsInstance(
            mail.get_connection('django.core.mail.backends.locmem.EmailBackend'),
            locmem.EmailBackend
        )
        self.assertIsInstance(mail.get_connection('django.core.mail.backends.dummy.EmailBackend'), dummy.EmailBackend)
        self.assertIsInstance(
            mail.get_connection('django.core.mail.backends.console.EmailBackend'),
            console.EmailBackend
        )
        tmp_dir = tempfile.mkdtemp()
        try:
            self.assertIsInstance(
                mail.get_connection('django.core.mail.backends.filebased.EmailBackend', file_path=tmp_dir),
                filebased.EmailBackend
            )
        finally:
            shutil.rmtree(tmp_dir)
        self.assertIsInstance(mail.get_connection(), locmem.EmailBackend)

    @override_settings(
        EMAIL_BACKEND='django.core.mail.backends.locmem.EmailBackend',
        ADMINS=[('nobody', 'nobody@example.com')],
        MANAGERS=[('nobody', 'nobody@example.com')])
    def test_connection_arg(self):
        """Test connection argument to send_mail(), et. al."""
        mail.outbox = []

        # Send using non-default connection
        connection = mail.get_connection('mail.custombackend.EmailBackend')
        send_mail('Subject', 'Content', 'from@example.com', ['to@example.com'], connection=connection)
        self.assertEqual(mail.outbox, [])
        self.assertEqual(len(connection.test_outbox), 1)
        self.assertEqual(connection.test_outbox[0].subject, 'Subject')

        connection = mail.get_connection('mail.custombackend.EmailBackend')
        send_mass_mail([
            ('Subject1', 'Content1', 'from1@example.com', ['to1@example.com']),
            ('Subject2', 'Content2', 'from2@example.com', ['to2@example.com']),
        ], connection=connection)
        self.assertEqual(mail.outbox, [])
        self.assertEqual(len(connection.test_outbox), 2)
        self.assertEqual(connection.test_outbox[0].subject, 'Subject1')
        self.assertEqual(connection.test_outbox[1].subject, 'Subject2')

        connection = mail.get_connection('mail.custombackend.EmailBackend')
        mail_admins('Admin message', 'Content', connection=connection)
        self.assertEqual(mail.outbox, [])
        self.assertEqual(len(connection.test_outbox), 1)
        self.assertEqual(connection.test_outbox[0].subject, '[Django] Admin message')

        connection = mail.get_connection('mail.custombackend.EmailBackend')
        mail_managers('Manager message', 'Content', connection=connection)
        self.assertEqual(mail.outbox, [])
        self.assertEqual(len(connection.test_outbox), 1)
        self.assertEqual(connection.test_outbox[0].subject, '[Django] Manager message')

    def test_dont_mangle_from_in_body(self):
        # Regression for #13433 - Make sure that EmailMessage doesn't mangle
        # 'From ' in message body.
        email = EmailMessage(
            'Subject', 'From the future', 'bounce@example.com', ['to@example.com'],
            headers={'From': 'from@example.com'},
        )
        self.assertNotIn(b'>From the future', email.message().as_bytes())

    def test_dont_base64_encode(self):
        # Ticket #3472
        # Shouldn't use Base64 encoding at all
        msg = EmailMessage(
            'Subject', 'UTF-8 encoded body', 'bounce@example.com', ['to@example.com'],
            headers={'From': 'from@example.com'},
        )
        self.assertIn(b'Content-Transfer-Encoding: 7bit', msg.message().as_bytes())

        # Ticket #11212
        # Shouldn't use quoted printable, should detect it can represent content with 7 bit data
        msg = EmailMessage(
            'Subject', 'Body with only ASCII characters.', 'bounce@example.com', ['to@example.com'],
            headers={'From': 'from@example.com'},
        )
        s = msg.message().as_bytes()
        self.assertIn(b'Content-Transfer-Encoding: 7bit', s)

        # Shouldn't use quoted printable, should detect it can represent content with 8 bit data
        msg = EmailMessage(
            'Subject', 'Body with latin characters: àáä.', 'bounce@example.com', ['to@example.com'],
            headers={'From': 'from@example.com'},
        )
        s = msg.message().as_bytes()
        self.assertIn(b'Content-Transfer-Encoding: 8bit', s)
        s = msg.message().as_string()
        self.assertIn(str('Content-Transfer-Encoding: 8bit'), s)

        msg = EmailMessage(
            'Subject', 'Body with non latin characters: А Б В Г Д Е Ж Ѕ З И І К Л М Н О П.', 'bounce@example.com',
            ['to@example.com'], headers={'From': 'from@example.com'},
        )
        s = msg.message().as_bytes()
        self.assertIn(b'Content-Transfer-Encoding: 8bit', s)
        s = msg.message().as_string()
        self.assertIn(str('Content-Transfer-Encoding: 8bit'), s)

    def test_dont_base64_encode_message_rfc822(self):
        # Ticket #18967
        # Shouldn't use base64 encoding for a child EmailMessage attachment.
        # Create a child message first
        child_msg = EmailMessage(
            'Child Subject', 'Some body of child message', 'bounce@example.com', ['to@example.com'],
            headers={'From': 'from@example.com'},
        )
        child_s = child_msg.message().as_string()

        # Now create a parent
        parent_msg = EmailMessage(
            'Parent Subject', 'Some parent body', 'bounce@example.com', ['to@example.com'],
            headers={'From': 'from@example.com'},
        )

        # Attach to parent as a string
        parent_msg.attach(content=child_s, mimetype='message/rfc822')
        parent_s = parent_msg.message().as_string()

        # The child message header is not base64 encoded
        self.assertIn(str('Child Subject'), parent_s)

        # Feature test: try attaching email.Message object directly to the mail.
        parent_msg = EmailMessage(
            'Parent Subject', 'Some parent body', 'bounce@example.com', ['to@example.com'],
            headers={'From': 'from@example.com'},
        )
        parent_msg.attach(content=child_msg.message(), mimetype='message/rfc822')
        parent_s = parent_msg.message().as_string()

        # The child message header is not base64 encoded
        self.assertIn(str('Child Subject'), parent_s)

        # Feature test: try attaching Django's EmailMessage object directly to the mail.
        parent_msg = EmailMessage(
            'Parent Subject', 'Some parent body', 'bounce@example.com', ['to@example.com'],
            headers={'From': 'from@example.com'},
        )
        parent_msg.attach(content=child_msg, mimetype='message/rfc822')
        parent_s = parent_msg.message().as_string()

        # The child message header is not base64 encoded
        self.assertIn(str('Child Subject'), parent_s)

    def test_sanitize_address(self):
        """
        Email addresses are properly sanitized.
        """
        # Simple ASCII address - string form
        self.assertEqual(sanitize_address('to@example.com', 'ascii'), 'to@example.com')
        self.assertEqual(sanitize_address('to@example.com', 'utf-8'), 'to@example.com')
        # Bytestrings are transformed to normal strings.
        self.assertEqual(sanitize_address(b'to@example.com', 'utf-8'), 'to@example.com')

        # Simple ASCII address - tuple form
        self.assertEqual(
            sanitize_address(('A name', 'to@example.com'), 'ascii'),
            'A name <to@example.com>'
        )
        self.assertEqual(
            sanitize_address(('A name', 'to@example.com'), 'utf-8'),
            '=?utf-8?q?A_name?= <to@example.com>'
        )

        # Unicode characters are are supported in RFC-6532.
        self.assertEqual(
            sanitize_address('tó@example.com', 'utf-8'),
            '=?utf-8?b?dMOz?=@example.com'
        )
        self.assertEqual(
            sanitize_address(('Tó Example', 'tó@example.com'), 'utf-8'),
            '=?utf-8?q?T=C3=B3_Example?= <=?utf-8?b?dMOz?=@example.com>'
        )


@requires_tz_support
class MailTimeZoneTests(SimpleTestCase):

    @override_settings(EMAIL_USE_LOCALTIME=False, USE_TZ=True, TIME_ZONE='Africa/Algiers')
    def test_date_header_utc(self):
        """
        EMAIL_USE_LOCALTIME=False creates a datetime in UTC.
        """
        email = EmailMessage('Subject', 'Body', 'bounce@example.com', ['to@example.com'])
        self.assertTrue(email.message()['Date'].endswith('-0000'))

    @override_settings(EMAIL_USE_LOCALTIME=True, USE_TZ=True, TIME_ZONE='Africa/Algiers')
    def test_date_header_localtime(self):
        """
        EMAIL_USE_LOCALTIME=True creates a datetime in the local time zone.
        """
        email = EmailMessage('Subject', 'Body', 'bounce@example.com', ['to@example.com'])
        self.assertTrue(email.message()['Date'].endswith('+0100'))  # Africa/Algiers is UTC+1


class PythonGlobalState(SimpleTestCase):
    """
    Tests for #12422 -- Django smarts (#2472/#11212) with charset of utf-8 text
    parts shouldn't pollute global email Python package charset registry when
    django.mail.message is imported.
    """

    def test_utf8(self):
        txt = MIMEText('UTF-8 encoded body', 'plain', 'utf-8')
        self.assertIn('Content-Transfer-Encoding: base64', txt.as_string())

    def test_7bit(self):
        txt = MIMEText('Body with only ASCII characters.', 'plain', 'utf-8')
        self.assertIn('Content-Transfer-Encoding: base64', txt.as_string())

    def test_8bit_latin(self):
        txt = MIMEText('Body with latin characters: àáä.', 'plain', 'utf-8')
        self.assertIn(str('Content-Transfer-Encoding: base64'), txt.as_string())

    def test_8bit_non_latin(self):
        txt = MIMEText('Body with non latin characters: А Б В Г Д Е Ж Ѕ З И І К Л М Н О П.', 'plain', 'utf-8')
        self.assertIn(str('Content-Transfer-Encoding: base64'), txt.as_string())


class BaseEmailBackendTests(HeadersCheckMixin, object):
    email_backend = None

    def setUp(self):
        self.settings_override = override_settings(EMAIL_BACKEND=self.email_backend)
        self.settings_override.enable()

    def tearDown(self):
        self.settings_override.disable()

    def assertStartsWith(self, first, second):
        if not first.startswith(second):
            self.longMessage = True
            self.assertEqual(first[:len(second)], second, "First string doesn't start with the second.")

    def get_mailbox_content(self):
        raise NotImplementedError('subclasses of BaseEmailBackendTests must provide a get_mailbox_content() method')

    def flush_mailbox(self):
        raise NotImplementedError('subclasses of BaseEmailBackendTests may require a flush_mailbox() method')

    def get_the_message(self):
        mailbox = self.get_mailbox_content()
        self.assertEqual(
            len(mailbox), 1,
            "Expected exactly one message, got %d.\n%r" % (len(mailbox), [m.as_string() for m in mailbox])
        )
        return mailbox[0]

    def test_send(self):
        email = EmailMessage('Subject', 'Content', 'from@example.com', ['to@example.com'])
        num_sent = mail.get_connection().send_messages([email])
        self.assertEqual(num_sent, 1)
        message = self.get_the_message()
        self.assertEqual(message["subject"], "Subject")
        self.assertEqual(message.get_payload(), "Content")
        self.assertEqual(message["from"], "from@example.com")
        self.assertEqual(message.get_all("to"), ["to@example.com"])

    def test_send_unicode(self):
        email = EmailMessage('Chère maman', 'Je t\'aime très fort', 'from@example.com', ['to@example.com'])
        num_sent = mail.get_connection().send_messages([email])
        self.assertEqual(num_sent, 1)
        message = self.get_the_message()
        self.assertEqual(message["subject"], '=?utf-8?q?Ch=C3=A8re_maman?=')
        self.assertEqual(force_text(message.get_payload(decode=True)), 'Je t\'aime très fort')

    def test_send_long_lines(self):
        """
        Email line length is limited to 998 chars by the RFC:
        https://tools.ietf.org/html/rfc5322#section-2.1.1
        Message body containing longer lines are converted to Quoted-Printable
        to avoid having to insert newlines, which could be hairy to do properly.
        """
        # Unencoded body length is < 998 (840) but > 998 when utf-8 encoded.
        email = EmailMessage('Subject', 'В южных морях ' * 60, 'from@example.com', ['to@example.com'])
        email.send()
        message = self.get_the_message()
        self.assertMessageHasHeaders(message, {
            ('MIME-Version', '1.0'),
            ('Content-Type', 'text/plain; charset="utf-8"'),
            ('Content-Transfer-Encoding', 'quoted-printable'),
        })

    def test_send_many(self):
        email1 = EmailMessage('Subject', 'Content1', 'from@example.com', ['to@example.com'])
        email2 = EmailMessage('Subject', 'Content2', 'from@example.com', ['to@example.com'])
        # send_messages() may take a list or a generator.
        emails_lists = ([email1, email2], (email for email in [email1, email2]))
        for emails_list in emails_lists:
            num_sent = mail.get_connection().send_messages(emails_list)
            self.assertEqual(num_sent, 2)
            messages = self.get_mailbox_content()
            self.assertEqual(len(messages), 2)
            self.assertEqual(messages[0].get_payload(), 'Content1')
            self.assertEqual(messages[1].get_payload(), 'Content2')
            self.flush_mailbox()

    def test_send_verbose_name(self):
        email = EmailMessage("Subject", "Content", '"Firstname Sürname" <from@example.com>',
                             ["to@example.com"])
        email.send()
        message = self.get_the_message()
        self.assertEqual(message["subject"], "Subject")
        self.assertEqual(message.get_payload(), "Content")
        self.assertEqual(message["from"], "=?utf-8?q?Firstname_S=C3=BCrname?= <from@example.com>")

    def test_plaintext_send_mail(self):
        """
        Test send_mail without the html_message
        regression test for adding html_message parameter to send_mail()
        """
        send_mail('Subject', 'Content', 'sender@example.com', ['nobody@example.com'])
        message = self.get_the_message()

        self.assertEqual(message.get('subject'), 'Subject')
        self.assertEqual(message.get_all('to'), ['nobody@example.com'])
        self.assertFalse(message.is_multipart())
        self.assertEqual(message.get_payload(), 'Content')
        self.assertEqual(message.get_content_type(), 'text/plain')

    def test_html_send_mail(self):
        """Test html_message argument to send_mail"""
        send_mail('Subject', 'Content', 'sender@example.com', ['nobody@example.com'], html_message='HTML Content')
        message = self.get_the_message()

        self.assertEqual(message.get('subject'), 'Subject')
        self.assertEqual(message.get_all('to'), ['nobody@example.com'])
        self.assertTrue(message.is_multipart())
        self.assertEqual(len(message.get_payload()), 2)
        self.assertEqual(message.get_payload(0).get_payload(), 'Content')
        self.assertEqual(message.get_payload(0).get_content_type(), 'text/plain')
        self.assertEqual(message.get_payload(1).get_payload(), 'HTML Content')
        self.assertEqual(message.get_payload(1).get_content_type(), 'text/html')

    @override_settings(MANAGERS=[('nobody', 'nobody@example.com')])
    def test_html_mail_managers(self):
        """Test html_message argument to mail_managers"""
        mail_managers('Subject', 'Content', html_message='HTML Content')
        message = self.get_the_message()

        self.assertEqual(message.get('subject'), '[Django] Subject')
        self.assertEqual(message.get_all('to'), ['nobody@example.com'])
        self.assertTrue(message.is_multipart())
        self.assertEqual(len(message.get_payload()), 2)
        self.assertEqual(message.get_payload(0).get_payload(), 'Content')
        self.assertEqual(message.get_payload(0).get_content_type(), 'text/plain')
        self.assertEqual(message.get_payload(1).get_payload(), 'HTML Content')
        self.assertEqual(message.get_payload(1).get_content_type(), 'text/html')

    @override_settings(ADMINS=[('nobody', 'nobody@example.com')])
    def test_html_mail_admins(self):
        """Test html_message argument to mail_admins """
        mail_admins('Subject', 'Content', html_message='HTML Content')
        message = self.get_the_message()

        self.assertEqual(message.get('subject'), '[Django] Subject')
        self.assertEqual(message.get_all('to'), ['nobody@example.com'])
        self.assertTrue(message.is_multipart())
        self.assertEqual(len(message.get_payload()), 2)
        self.assertEqual(message.get_payload(0).get_payload(), 'Content')
        self.assertEqual(message.get_payload(0).get_content_type(), 'text/plain')
        self.assertEqual(message.get_payload(1).get_payload(), 'HTML Content')
        self.assertEqual(message.get_payload(1).get_content_type(), 'text/html')

    @override_settings(
        ADMINS=[('nobody', 'nobody+admin@example.com')],
        MANAGERS=[('nobody', 'nobody+manager@example.com')])
    def test_manager_and_admin_mail_prefix(self):
        """
        String prefix + lazy translated subject = bad output
        Regression for #13494
        """
        mail_managers(ugettext_lazy('Subject'), 'Content')
        message = self.get_the_message()
        self.assertEqual(message.get('subject'), '[Django] Subject')

        self.flush_mailbox()
        mail_admins(ugettext_lazy('Subject'), 'Content')
        message = self.get_the_message()
        self.assertEqual(message.get('subject'), '[Django] Subject')

    @override_settings(ADMINS=[], MANAGERS=[])
    def test_empty_admins(self):
        """
        mail_admins/mail_managers doesn't connect to the mail server
        if there are no recipients (#9383)
        """
        mail_admins('hi', 'there')
        self.assertEqual(self.get_mailbox_content(), [])
        mail_managers('hi', 'there')
        self.assertEqual(self.get_mailbox_content(), [])

    def test_message_cc_header(self):
        """
        Regression test for #7722
        """
        email = EmailMessage('Subject', 'Content', 'from@example.com', ['to@example.com'], cc=['cc@example.com'])
        mail.get_connection().send_messages([email])
        message = self.get_the_message()
        self.assertMessageHasHeaders(message, {
            ('MIME-Version', '1.0'),
            ('Content-Type', 'text/plain; charset="utf-8"'),
            ('Content-Transfer-Encoding', '7bit'),
            ('Subject', 'Subject'),
            ('From', 'from@example.com'),
            ('To', 'to@example.com'),
            ('Cc', 'cc@example.com')})
        self.assertIn('\nDate: ', message.as_string())

    def test_idn_send(self):
        """
        Regression test for #14301
        """
        self.assertTrue(send_mail('Subject', 'Content', 'from@öäü.com', ['to@öäü.com']))
        message = self.get_the_message()
        self.assertEqual(message.get('subject'), 'Subject')
        self.assertEqual(message.get('from'), 'from@xn--4ca9at.com')
        self.assertEqual(message.get('to'), 'to@xn--4ca9at.com')

        self.flush_mailbox()
        m = EmailMessage('Subject', 'Content', 'from@öäü.com', ['to@öäü.com'], cc=['cc@öäü.com'])
        m.send()
        message = self.get_the_message()
        self.assertEqual(message.get('subject'), 'Subject')
        self.assertEqual(message.get('from'), 'from@xn--4ca9at.com')
        self.assertEqual(message.get('to'), 'to@xn--4ca9at.com')
        self.assertEqual(message.get('cc'), 'cc@xn--4ca9at.com')

    def test_recipient_without_domain(self):
        """
        Regression test for #15042
        """
        self.assertTrue(send_mail("Subject", "Content", "tester", ["django"]))
        message = self.get_the_message()
        self.assertEqual(message.get('subject'), 'Subject')
        self.assertEqual(message.get('from'), "tester")
        self.assertEqual(message.get('to'), "django")

    def test_lazy_addresses(self):
        """
        Email sending should support lazy email addresses (#24416).
        """
        _ = ugettext_lazy
        self.assertTrue(send_mail('Subject', 'Content', _('tester'), [_('django')]))
        message = self.get_the_message()
        self.assertEqual(message.get('from'), 'tester')
        self.assertEqual(message.get('to'), 'django')

        self.flush_mailbox()
        m = EmailMessage(
            'Subject', 'Content', _('tester'), [_('to1'), _('to2')],
            cc=[_('cc1'), _('cc2')],
            bcc=[_('bcc')],
            reply_to=[_('reply')],
        )
        self.assertEqual(m.recipients(), ['to1', 'to2', 'cc1', 'cc2', 'bcc'])
        m.send()
        message = self.get_the_message()
        self.assertEqual(message.get('from'), 'tester')
        self.assertEqual(message.get('to'), 'to1, to2')
        self.assertEqual(message.get('cc'), 'cc1, cc2')
        self.assertEqual(message.get('Reply-To'), 'reply')

    def test_close_connection(self):
        """
        Connection can be closed (even when not explicitly opened)
        """
        conn = mail.get_connection(username='', password='')
        conn.close()

    def test_use_as_contextmanager(self):
        """
        The connection can be used as a contextmanager.
        """
        opened = [False]
        closed = [False]
        conn = mail.get_connection(username='', password='')

        def open():
            opened[0] = True
        conn.open = open

        def close():
            closed[0] = True
        conn.close = close
        with conn as same_conn:
            self.assertTrue(opened[0])
            self.assertIs(same_conn, conn)
            self.assertFalse(closed[0])
        self.assertTrue(closed[0])


class LocmemBackendTests(BaseEmailBackendTests, SimpleTestCase):
    email_backend = 'django.core.mail.backends.locmem.EmailBackend'

    def get_mailbox_content(self):
        return [m.message() for m in mail.outbox]

    def flush_mailbox(self):
        mail.outbox = []

    def tearDown(self):
        super(LocmemBackendTests, self).tearDown()
        mail.outbox = []

    def test_locmem_shared_messages(self):
        """
        Make sure that the locmen backend populates the outbox.
        """
        connection = locmem.EmailBackend()
        connection2 = locmem.EmailBackend()
        email = EmailMessage(
            'Subject', 'Content', 'bounce@example.com', ['to@example.com'],
            headers={'From': 'from@example.com'},
        )
        connection.send_messages([email])
        connection2.send_messages([email])
        self.assertEqual(len(mail.outbox), 2)

    def test_validate_multiline_headers(self):
        # Ticket #18861 - Validate emails when using the locmem backend
        with self.assertRaises(BadHeaderError):
            send_mail('Subject\nMultiline', 'Content', 'from@example.com', ['to@example.com'])


class FileBackendTests(BaseEmailBackendTests, SimpleTestCase):
    email_backend = 'django.core.mail.backends.filebased.EmailBackend'

    def setUp(self):
        super(FileBackendTests, self).setUp()
        self.tmp_dir = tempfile.mkdtemp()
        self.addCleanup(shutil.rmtree, self.tmp_dir)
        self._settings_override = override_settings(EMAIL_FILE_PATH=self.tmp_dir)
        self._settings_override.enable()

    def tearDown(self):
        self._settings_override.disable()
        super(FileBackendTests, self).tearDown()

    def flush_mailbox(self):
        for filename in os.listdir(self.tmp_dir):
            os.unlink(os.path.join(self.tmp_dir, filename))

    def get_mailbox_content(self):
        messages = []
        for filename in os.listdir(self.tmp_dir):
            with open(os.path.join(self.tmp_dir, filename), 'rb') as fp:
                session = fp.read().split(force_bytes('\n' + ('-' * 79) + '\n', encoding='ascii'))
            messages.extend(message_from_bytes(m) for m in session if m)
        return messages

    def test_file_sessions(self):
        """Make sure opening a connection creates a new file"""
        msg = EmailMessage(
            'Subject', 'Content', 'bounce@example.com', ['to@example.com'],
            headers={'From': 'from@example.com'},
        )
        connection = mail.get_connection()
        connection.send_messages([msg])

        self.assertEqual(len(os.listdir(self.tmp_dir)), 1)
        with open(os.path.join(self.tmp_dir, os.listdir(self.tmp_dir)[0]), 'rb') as fp:
            message = message_from_binary_file(fp)
        self.assertEqual(message.get_content_type(), 'text/plain')
        self.assertEqual(message.get('subject'), 'Subject')
        self.assertEqual(message.get('from'), 'from@example.com')
        self.assertEqual(message.get('to'), 'to@example.com')

        connection2 = mail.get_connection()
        connection2.send_messages([msg])
        self.assertEqual(len(os.listdir(self.tmp_dir)), 2)

        connection.send_messages([msg])
        self.assertEqual(len(os.listdir(self.tmp_dir)), 2)

        msg.connection = mail.get_connection()
        self.assertTrue(connection.open())
        msg.send()
        self.assertEqual(len(os.listdir(self.tmp_dir)), 3)
        msg.send()
        self.assertEqual(len(os.listdir(self.tmp_dir)), 3)

        connection.close()


class ConsoleBackendTests(BaseEmailBackendTests, SimpleTestCase):
    email_backend = 'django.core.mail.backends.console.EmailBackend'

    def setUp(self):
        super(ConsoleBackendTests, self).setUp()
        self.__stdout = sys.stdout
        self.stream = sys.stdout = StringIO()

    def tearDown(self):
        del self.stream
        sys.stdout = self.__stdout
        del self.__stdout
        super(ConsoleBackendTests, self).tearDown()

    def flush_mailbox(self):
        self.stream = sys.stdout = StringIO()

    def get_mailbox_content(self):
        messages = self.stream.getvalue().split(str('\n' + ('-' * 79) + '\n'))
        return [message_from_bytes(force_bytes(m)) for m in messages if m]

    def test_console_stream_kwarg(self):
        """
        The console backend can be pointed at an arbitrary stream.
        """
        s = StringIO()
        connection = mail.get_connection('django.core.mail.backends.console.EmailBackend', stream=s)
        send_mail('Subject', 'Content', 'from@example.com', ['to@example.com'], connection=connection)
        message = force_bytes(s.getvalue().split('\n' + ('-' * 79) + '\n')[0])
        self.assertMessageHasHeaders(message, {
            ('MIME-Version', '1.0'),
            ('Content-Type', 'text/plain; charset="utf-8"'),
            ('Content-Transfer-Encoding', '7bit'),
            ('Subject', 'Subject'),
            ('From', 'from@example.com'),
            ('To', 'to@example.com')})
        self.assertIn(b'\nDate: ', message)


class FakeSMTPChannel(smtpd.SMTPChannel):

    def collect_incoming_data(self, data):
        try:
            smtpd.SMTPChannel.collect_incoming_data(self, data)
        except UnicodeDecodeError:
            # ignore decode error in SSL/TLS connection tests as we only care
            # whether the connection attempt was made
            pass

    def smtp_AUTH(self, arg):
        if arg == 'CRAM-MD5':
            # This is only the first part of the login process. But it's enough
            # for our tests.
            challenge = base64.b64encode(b'somerandomstring13579')
            self.push(str('334 %s' % challenge.decode()))
        else:
            self.push(str('502 Error: login "%s" not implemented' % arg))


class FakeSMTPServer(smtpd.SMTPServer, threading.Thread):
    """
    Asyncore SMTP server wrapped into a thread. Based on DummyFTPServer from:
    http://svn.python.org/view/python/branches/py3k/Lib/test/test_ftplib.py?revision=86061&view=markup
    """
    channel_class = FakeSMTPChannel

    def __init__(self, *args, **kwargs):
        threading.Thread.__init__(self)
        # New kwarg added in Python 3.5; default switching to False in 3.6.
        if sys.version_info >= (3, 5):
            kwargs['decode_data'] = True
        smtpd.SMTPServer.__init__(self, *args, **kwargs)
        self._sink = []
        self.active = False
        self.active_lock = threading.Lock()
        self.sink_lock = threading.Lock()

    def process_message(self, peer, mailfrom, rcpttos, data):
        data = data.encode('utf-8')
        m = message_from_bytes(data)
        maddr = parseaddr(m.get('from'))[1]

        if mailfrom != maddr:
            # According to the spec, mailfrom does not necessarily match the
            # From header - on Python 3 this is the case where the local part
            # isn't encoded, so try to correct that.
            lp, domain = mailfrom.split('@', 1)
            lp = Header(lp, 'utf-8').encode()
            mailfrom = '@'.join([lp, domain])

        if mailfrom != maddr:
            return "553 '%s' != '%s'" % (mailfrom, maddr)
        with self.sink_lock:
            self._sink.append(m)

    def get_sink(self):
        with self.sink_lock:
            return self._sink[:]

    def flush_sink(self):
        with self.sink_lock:
            self._sink[:] = []

    def start(self):
        assert not self.active
        self.__flag = threading.Event()
        threading.Thread.start(self)
        self.__flag.wait()

    def run(self):
        self.active = True
        self.__flag.set()
        while self.active and asyncore.socket_map:
            with self.active_lock:
                asyncore.loop(timeout=0.1, count=1)
        asyncore.close_all()

    def stop(self):
        if self.active:
            self.active = False
            self.join()


class FakeAUTHSMTPConnection(SMTP):
    """
    A SMTP connection pretending support for the AUTH command. It does not, but
    at least this can allow testing the first part of the AUTH process.
    """

    def ehlo(self, name=''):
        response = SMTP.ehlo(self, name=name)
        self.esmtp_features.update({
            'auth': 'CRAM-MD5 PLAIN LOGIN',
        })
        return response


class SMTPBackendTestsBase(SimpleTestCase):

    @classmethod
    def setUpClass(cls):
        super(SMTPBackendTestsBase, cls).setUpClass()
        cls.server = FakeSMTPServer(('127.0.0.1', 0), None)
        cls._settings_override = override_settings(
            EMAIL_HOST="127.0.0.1",
            EMAIL_PORT=cls.server.socket.getsockname()[1])
        cls._settings_override.enable()
        cls.server.start()

    @classmethod
    def tearDownClass(cls):
        cls._settings_override.disable()
        cls.server.stop()
        super(SMTPBackendTestsBase, cls).tearDownClass()


class SMTPBackendTests(BaseEmailBackendTests, SMTPBackendTestsBase):
    email_backend = 'django.core.mail.backends.smtp.EmailBackend'

    def setUp(self):
        super(SMTPBackendTests, self).setUp()
        self.server.flush_sink()

    def tearDown(self):
        self.server.flush_sink()
        super(SMTPBackendTests, self).tearDown()

    def flush_mailbox(self):
        self.server.flush_sink()

    def get_mailbox_content(self):
        return self.server.get_sink()

    @override_settings(
        EMAIL_HOST_USER="not empty username",
        EMAIL_HOST_PASSWORD="not empty password")
    def test_email_authentication_use_settings(self):
        backend = smtp.EmailBackend()
        self.assertEqual(backend.username, 'not empty username')
        self.assertEqual(backend.password, 'not empty password')

    @override_settings(
        EMAIL_HOST_USER="not empty username",
        EMAIL_HOST_PASSWORD="not empty password")
    def test_email_authentication_override_settings(self):
        backend = smtp.EmailBackend(username='username', password='password')
        self.assertEqual(backend.username, 'username')
        self.assertEqual(backend.password, 'password')

    @override_settings(
        EMAIL_HOST_USER="not empty username",
        EMAIL_HOST_PASSWORD="not empty password")
    def test_email_disabled_authentication(self):
        backend = smtp.EmailBackend(username='', password='')
        self.assertEqual(backend.username, '')
        self.assertEqual(backend.password, '')

    def test_auth_attempted(self):
        """
        Opening the backend with non empty username/password tries
        to authenticate against the SMTP server.
        """
        backend = smtp.EmailBackend(
            username='not empty username', password='not empty password')
        with self.assertRaisesMessage(SMTPException, 'SMTP AUTH extension not supported by server.'):
            with backend:
                pass

    def test_server_open(self):
        """
        open() returns whether it opened a connection.
        """
        backend = smtp.EmailBackend(username='', password='')
        self.assertFalse(backend.connection)
        opened = backend.open()
        backend.close()
        self.assertTrue(opened)

    def test_server_login(self):
        """
        Even if the Python SMTP server doesn't support authentication, the
        login process starts and the appropriate exception is raised.
        """
        class CustomEmailBackend(smtp.EmailBackend):
            connection_class = FakeAUTHSMTPConnection

        backend = CustomEmailBackend(username='username', password='password')
        with self.assertRaises(SMTPAuthenticationError):
            with backend:
                pass

    @override_settings(EMAIL_USE_TLS=True)
    def test_email_tls_use_settings(self):
        backend = smtp.EmailBackend()
        self.assertTrue(backend.use_tls)

    @override_settings(EMAIL_USE_TLS=True)
    def test_email_tls_override_settings(self):
        backend = smtp.EmailBackend(use_tls=False)
        self.assertFalse(backend.use_tls)

    def test_email_tls_default_disabled(self):
        backend = smtp.EmailBackend()
        self.assertFalse(backend.use_tls)

    @override_settings(EMAIL_USE_SSL=True)
    def test_email_ssl_use_settings(self):
        backend = smtp.EmailBackend()
        self.assertTrue(backend.use_ssl)

    @override_settings(EMAIL_USE_SSL=True)
    def test_email_ssl_override_settings(self):
        backend = smtp.EmailBackend(use_ssl=False)
        self.assertFalse(backend.use_ssl)

    def test_email_ssl_default_disabled(self):
        backend = smtp.EmailBackend()
        self.assertFalse(backend.use_ssl)

    @override_settings(EMAIL_SSL_CERTFILE='foo')
    def test_email_ssl_certfile_use_settings(self):
        backend = smtp.EmailBackend()
        self.assertEqual(backend.ssl_certfile, 'foo')

    @override_settings(EMAIL_SSL_CERTFILE='foo')
    def test_email_ssl_certfile_override_settings(self):
        backend = smtp.EmailBackend(ssl_certfile='bar')
        self.assertEqual(backend.ssl_certfile, 'bar')

    def test_email_ssl_certfile_default_disabled(self):
        backend = smtp.EmailBackend()
        self.assertIsNone(backend.ssl_certfile)

    @override_settings(EMAIL_SSL_KEYFILE='foo')
    def test_email_ssl_keyfile_use_settings(self):
        backend = smtp.EmailBackend()
        self.assertEqual(backend.ssl_keyfile, 'foo')

    @override_settings(EMAIL_SSL_KEYFILE='foo')
    def test_email_ssl_keyfile_override_settings(self):
        backend = smtp.EmailBackend(ssl_keyfile='bar')
        self.assertEqual(backend.ssl_keyfile, 'bar')

    def test_email_ssl_keyfile_default_disabled(self):
        backend = smtp.EmailBackend()
        self.assertIsNone(backend.ssl_keyfile)

    @override_settings(EMAIL_USE_TLS=True)
    def test_email_tls_attempts_starttls(self):
        backend = smtp.EmailBackend()
        self.assertTrue(backend.use_tls)
        with self.assertRaisesMessage(SMTPException, 'STARTTLS extension not supported by server.'):
            with backend:
                pass

    @override_settings(EMAIL_USE_SSL=True)
    def test_email_ssl_attempts_ssl_connection(self):
        backend = smtp.EmailBackend()
        self.assertTrue(backend.use_ssl)
        with self.assertRaises(SSLError):
            with backend:
                pass

    def test_connection_timeout_default(self):
        """The connection's timeout value is None by default."""
        connection = mail.get_connection('django.core.mail.backends.smtp.EmailBackend')
        self.assertIsNone(connection.timeout)

    def test_connection_timeout_custom(self):
        """The timeout parameter can be customized."""
        class MyEmailBackend(smtp.EmailBackend):
            def __init__(self, *args, **kwargs):
                kwargs.setdefault('timeout', 42)
                super(MyEmailBackend, self).__init__(*args, **kwargs)

        myemailbackend = MyEmailBackend()
        myemailbackend.open()
        self.assertEqual(myemailbackend.timeout, 42)
        self.assertEqual(myemailbackend.connection.timeout, 42)
        myemailbackend.close()

    @override_settings(EMAIL_TIMEOUT=10)
    def test_email_timeout_override_settings(self):
        backend = smtp.EmailBackend()
        self.assertEqual(backend.timeout, 10)

    def test_email_msg_uses_crlf(self):
        """#23063 -- RFC-compliant messages are sent over SMTP."""
        send = SMTP.send
        try:
            smtp_messages = []

            def mock_send(self, s):
                smtp_messages.append(s)
                return send(self, s)

            SMTP.send = mock_send

            email = EmailMessage('Subject', 'Content', 'from@example.com', ['to@example.com'])
            mail.get_connection().send_messages([email])

            # Find the actual message
            msg = None
            for i, m in enumerate(smtp_messages):
                if m[:4] == 'data':
                    msg = smtp_messages[i + 1]
                    break

            self.assertTrue(msg)

            msg = msg.decode('utf-8')
            # The message only contains CRLF and not combinations of CRLF, LF, and CR.
            msg = msg.replace('\r\n', '')
            self.assertNotIn('\r', msg)
            self.assertNotIn('\n', msg)

        finally:
            SMTP.send = send

    def test_send_messages_after_open_failed(self):
        """
        send_messages() shouldn't try to send messages if open() raises an
        exception after initializing the connection.
        """
        backend = smtp.EmailBackend()
        # Simulate connection initialization success and a subsequent
        # connection exception.
        backend.connection = True
        backend.open = lambda: None
        email = EmailMessage('Subject', 'Content', 'from@example.com', ['to@example.com'])
        self.assertEqual(backend.send_messages([email]), None)


class SMTPBackendStoppedServerTests(SMTPBackendTestsBase):
    """
    These tests require a separate class, because the FakeSMTPServer is shut
    down in setUpClass(), and it cannot be restarted ("RuntimeError: threads
    can only be started once").
    """
    @classmethod
    def setUpClass(cls):
        super(SMTPBackendStoppedServerTests, cls).setUpClass()
        cls.backend = smtp.EmailBackend(username='', password='')
        cls.server.stop()

    def test_server_stopped(self):
        """
        Closing the backend while the SMTP server is stopped doesn't raise an
        exception.
        """
        self.backend.close()

    def test_fail_silently_on_connection_error(self):
        """
        A socket connection error is silenced with fail_silently=True.
        """
        with self.assertRaises(socket.error):
            self.backend.open()
        self.backend.fail_silently = True
        self.backend.open()