diff --git a/django/core/mail/backends/smtp.py b/django/core/mail/backends/smtp.py
index e456b7864e..57ee967728 100644
--- a/django/core/mail/backends/smtp.py
+++ b/django/core/mail/backends/smtp.py
@@ -7,7 +7,6 @@ from django.conf import settings
 from django.core.mail.backends.base import BaseEmailBackend
 from django.core.mail.utils import DNS_NAME
 from django.core.mail.message import sanitize_address
-from django.utils.encoding import force_bytes
 
 
 class EmailBackend(BaseEmailBackend):
@@ -107,11 +106,9 @@ class EmailBackend(BaseEmailBackend):
         recipients = [sanitize_address(addr, email_message.encoding)
                       for addr in email_message.recipients()]
         message = email_message.message()
-        charset = message.get_charset().get_output_charset() if message.get_charset() else 'utf-8'
         try:
-            self.connection.sendmail(from_email, recipients,
-                    force_bytes(message.as_string(), charset))
-        except:
+            self.connection.sendmail(from_email, recipients, message.as_bytes())
+        except smtplib.SMTPException:
             if not self.fail_silently:
                 raise
             return False
diff --git a/django/core/mail/message.py b/django/core/mail/message.py
index 3450ecf6e0..95762ff89d 100644
--- a/django/core/mail/message.py
+++ b/django/core/mail/message.py
@@ -130,21 +130,25 @@ class MIMEMixin():
         This overrides the default as_string() implementation to not mangle
         lines that begin with 'From '. See bug #13433 for details.
         """
-        # Using a normal Generator on python 3 will yield a string, which will
-        # get base64 encoded in some cases to ensure that it's always convertable
-        # to ascii. We don't want base64 encoded emails, so we use a BytesGenertor
-        # which will do the right thing and then decode according to our known
-        # encoding. See #21093 and #3472 for details.
-        if six.PY3 and sys.version_info >= (3, 3, 3):
+        fp = six.StringIO()
+        g = generator.Generator(fp, mangle_from_=False)
+        g.flatten(self, unixfrom=unixfrom)
+        return fp.getvalue()
+
+    if six.PY2:
+        as_bytes = as_string
+    else:
+        def as_bytes(self, unixfrom=False):
+            """Return the entire formatted message as bytes.
+            Optional `unixfrom' when True, means include the Unix From_ envelope
+            header.
+
+            This overrides the default as_bytes() implementation to not mangle
+            lines that begin with 'From '. See bug #13433 for details.
+            """
             fp = six.BytesIO()
             g = generator.BytesGenerator(fp, mangle_from_=False)
             g.flatten(self, unixfrom=unixfrom)
-            encoding = self.get_charset().get_output_charset() if self.get_charset() else 'utf-8'
-            return fp.getvalue().decode(encoding)
-        else:
-            fp = six.StringIO()
-            g = generator.Generator(fp, mangle_from_=False)
-            g.flatten(self, unixfrom=unixfrom)
             return fp.getvalue()
 
 
@@ -158,9 +162,8 @@ class SafeMIMEText(MIMEMixin, MIMEText):
             # We do it manually and trigger re-encoding of the payload.
             MIMEText.__init__(self, text, subtype, None)
             del self['Content-Transfer-Encoding']
-            # Work around a bug in python 3.3.3 [sic], see
-            # http://bugs.python.org/issue19063 for details.
-            if sys.version_info[:3] == (3, 3, 3):
+            # Workaround for versions without http://bugs.python.org/issue19063
+            if (3, 2) < sys.version_info < (3, 3, 4):
                 payload = text.encode(utf8_charset.output_charset)
                 self._payload = payload.decode('ascii', 'surrogateescape')
                 self.set_charset(utf8_charset)
diff --git a/tests/mail/tests.py b/tests/mail/tests.py
index 01dbeb01e0..25f3b21a32 100644
--- a/tests/mail/tests.py
+++ b/tests/mail/tests.py
@@ -15,14 +15,38 @@ from django.core.mail import (EmailMessage, mail_admins, mail_managers,
         EmailMultiAlternatives, send_mail, send_mass_mail)
 from django.core.mail.backends import console, dummy, locmem, filebased, smtp
 from django.core.mail.message import BadHeaderError
-from django.test import TestCase
+from django.test import SimpleTestCase
 from django.test.utils import override_settings
-from django.utils.encoding import force_str, force_text
-from django.utils.six import PY3, StringIO
+from django.utils.encoding import force_str, force_text, force_bytes
+from django.utils.six import PY3, StringIO, binary_type
 from django.utils.translation import ugettext_lazy
 
+if PY3:
+    from email.utils import parseaddr
+    from email import message_from_bytes
+else:
+    from email.Utils import parseaddr
+    message_from_bytes = email.message_from_string
 
-class MailTests(TestCase):
+
+class HeadersCheckMixin(object):
+
+    def assertMessageHasHeaders(self, message, headers):
+        """
+        Check that :param message: has all :param headers: headers.
+
+        :param message: can be an instance of an email.Message subclass or a
+        string with the contens of an email message.
+        :param headers: should be a set of (header-name, header-value) tuples.
+        """
+        if isinstance(message, binary_type):
+            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.
     """
@@ -191,8 +215,18 @@ class MailTests(TestCase):
         msg = EmailMultiAlternatives('Subject', text_content, 'from@example.com', ['to@example.com'])
         msg.encoding = 'iso-8859-1'
         msg.attach_alternative(html_content, "text/html")
-        self.assertEqual(msg.message().get_payload(0).as_string(), 'Content-Type: text/plain; charset="iso-8859-1"\nMIME-Version: 1.0\nContent-Transfer-Encoding: quoted-printable\n\nFirstname S=FCrname is a great guy.')
-        self.assertEqual(msg.message().get_payload(1).as_string(), 'Content-Type: text/html; charset="iso-8859-1"\nMIME-Version: 1.0\nContent-Transfer-Encoding: quoted-printable\n\n<p>Firstname S=FCrname is a <strong>great</strong> guy.</p>')
+        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"""
@@ -203,8 +237,8 @@ class MailTests(TestCase):
         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_str = msg.message().as_string()
-        message = email.message_from_string(msg_str)
+        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')
@@ -220,8 +254,8 @@ class MailTests(TestCase):
         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_str = msg.message().as_string()
-        message = email.message_from_string(msg_str)
+        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')
 
@@ -303,31 +337,31 @@ class MailTests(TestCase):
         # 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.assertFalse('>From the future' in email.message().as_string())
+        self.assertFalse(b'>From the future' in 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.assertFalse('Content-Transfer-Encoding: base64' in msg.message().as_string())
+        self.assertFalse(b'Content-Transfer-Encoding: base64' in 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_string()
-        self.assertFalse('Content-Transfer-Encoding: quoted-printable' in s)
-        self.assertTrue('Content-Transfer-Encoding: 7bit' in s)
+        s = msg.message().as_bytes()
+        self.assertFalse(b'Content-Transfer-Encoding: quoted-printable' in s)
+        self.assertTrue(b'Content-Transfer-Encoding: 7bit' in 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_string()
-        self.assertFalse(str('Content-Transfer-Encoding: quoted-printable') in s)
-        self.assertTrue(str('Content-Transfer-Encoding: 8bit') in s)
+        s = msg.message().as_bytes()
+        self.assertFalse(b'Content-Transfer-Encoding: quoted-printable' in s)
+        self.assertTrue(b'Content-Transfer-Encoding: 8bit' in 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_string()
-        self.assertFalse(str('Content-Transfer-Encoding: quoted-printable') in s)
-        self.assertTrue(str('Content-Transfer-Encoding: 8bit') in s)
+        s = msg.message().as_bytes()
+        self.assertFalse(b'Content-Transfer-Encoding: quoted-printable' in s)
+        self.assertTrue(b'Content-Transfer-Encoding: 8bit' in s)
 
 
 class BaseEmailBackendTests(object):
@@ -374,7 +408,7 @@ class BaseEmailBackendTests(object):
         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()), 'Je t\'aime très fort')
+        self.assertEqual(force_text(message.get_payload(decode=True)), 'Je t\'aime très fort')
 
     def test_send_many(self):
         email1 = EmailMessage('Subject', 'Content1', 'from@example.com', ['to@example.com'])
@@ -503,7 +537,7 @@ class BaseEmailBackendTests(object):
             self.fail("close() unexpectedly raised an exception: %s" % e)
 
 
-class LocmemBackendTests(BaseEmailBackendTests, TestCase):
+class LocmemBackendTests(BaseEmailBackendTests, SimpleTestCase):
     email_backend = 'django.core.mail.backends.locmem.EmailBackend'
 
     def get_mailbox_content(self):
@@ -533,7 +567,7 @@ class LocmemBackendTests(BaseEmailBackendTests, TestCase):
             send_mail('Subject\nMultiline', 'Content', 'from@example.com', ['to@example.com'])
 
 
-class FileBackendTests(BaseEmailBackendTests, TestCase):
+class FileBackendTests(BaseEmailBackendTests, SimpleTestCase):
     email_backend = 'django.core.mail.backends.filebased.EmailBackend'
 
     def setUp(self):
@@ -590,7 +624,7 @@ class FileBackendTests(BaseEmailBackendTests, TestCase):
         connection.close()
 
 
-class ConsoleBackendTests(BaseEmailBackendTests, TestCase):
+class ConsoleBackendTests(BaseEmailBackendTests, SimpleTestCase):
     email_backend = 'django.core.mail.backends.console.EmailBackend'
 
     def setUp(self):
@@ -608,8 +642,8 @@ class ConsoleBackendTests(BaseEmailBackendTests, TestCase):
         self.stream = sys.stdout = StringIO()
 
     def get_mailbox_content(self):
-        messages = force_text(self.stream.getvalue()).split('\n' + ('-' * 79) + '\n')
-        return [email.message_from_string(force_str(m)) for m in messages if m]
+        messages = self.stream.getvalue().split(force_str('\n' + ('-' * 79) + '\n'))
+        return [message_from_bytes(force_bytes(m)) for m in messages if m]
 
     def test_console_stream_kwarg(self):
         """
@@ -636,11 +670,10 @@ class FakeSMTPServer(smtpd.SMTPServer, threading.Thread):
         self.sink_lock = threading.Lock()
 
     def process_message(self, peer, mailfrom, rcpttos, data):
-        m = email.message_from_string(data)
         if PY3:
-            maddr = email.utils.parseaddr(m.get('from'))[1]
-        else:
-            maddr = email.Utils.parseaddr(m.get('from'))[1]
+            data = data.encode('utf-8')
+        m = message_from_bytes(data)
+        maddr = parseaddr(m.get('from'))[1]
         if mailfrom != maddr:
             return "553 '%s' != '%s'" % (mailfrom, maddr)
         with self.sink_lock:
@@ -674,7 +707,7 @@ class FakeSMTPServer(smtpd.SMTPServer, threading.Thread):
             self.join()
 
 
-class SMTPBackendTests(BaseEmailBackendTests, TestCase):
+class SMTPBackendTests(BaseEmailBackendTests, SimpleTestCase):
     email_backend = 'django.core.mail.backends.smtp.EmailBackend'
 
     @classmethod