diff --git a/.travis.yml b/.travis.yml
index 3501212..6d1d0f0 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,42 +1,51 @@
+version: ~> 1.0
+os: linux
 language: python
-python: '3.5'
+
+jobs:
+  # sort by django version, next to by python version
+  # Django 1.11 support all supported Python interpreter
+  - env: TOX_ENV=django111-py35
+    python: 3.5
+  - env: TOX_ENV=django111-py36
+    python: 3.6
+  # Django 2.0 support 3.5, 3.6
+  - env: TOX_ENV=django20-py35
+    python: 3.5
+  - env: TOX_ENV=django20-py36
+    python: 3.6
+
+  # Django 2.1 support Python 3.5, 3.6, 3.7
+  - env: TOX_ENV=django21-py35
+    python: 3.5
+  - env: TOX_ENV=django21-py36
+    python: 3.6
+  - env: TOX_ENV=django21-py37
+    python: 3.7
+  # Django 2.2 support Python 3.5, 3.6, 3.7
+  - env: TOX_ENV=django22-py35
+    python: 3.5
+  - env: TOX_ENV=django22-py36
+    python: 3.6
+  - env: TOX_ENV=django22-py37
+    python: 3.7
+  # Django 3.0 (beta) support Python 3.6, 3.7, 3.8
+  - env: TOX_ENV=django30-py36
+    python: 3.6
+  - env: TOX_ENV=django30-py37
+    python: 3.7
+  - env: TOX_ENV=django30-py38
+    python: 3.8
 
 env:
-  matrix:
-# sort by django version, next to by python version
-# Django 1.7 support Python 2.7, 3.4
-  - TOX_ENV=django17-py27
-  - TOX_ENV=django17-py34
-# Django 1.8 support Python 2.7, 3.4, 3.5
-  - TOX_ENV=django18-py27
-  - TOX_ENV=django18-py34
-  - TOX_ENV=django18-py35
-# Django 1.9 support Python 2.7, 3.4, 3.5
-  - TOX_ENV=django19-py27
-  - TOX_ENV=django19-py34
-  - TOX_ENV=django19-py35
-# Django 1.10 support Python 2.7, 3.4, 3.5
-  - TOX_ENV=django110-py27
-  - TOX_ENV=django110-py34
-  - TOX_ENV=django110-py35
-# Django 1.11 support all supported Python interpreter
-# Django 2.0 support Python 3.4, 3.5, 3.6
-  - TOX_ENV=django111-py34
-  - TOX_ENV=django111-py35
-  - TOX_ENV=django111-py36
-
   global:
-  - secure: aswHU7pQroGM+GHoYlhXzzk2FYfqxXJORjqXPsbgoHAIu4Bssaj8+YAzIcdy3j9kSt4I8VBpjnn8H/wzQXki75JBZOosQrIeMK018+uR+ZMONBLqDYW/N7EJHLgZt9QXxQNKeZygrD4GN/Dc4gLHGvPQC/RfPuuHcnF0Liaahoo=
-  - secure: RZ6M6984P885GRoyx9n/WCCWGoFAzYpS8sZkXu3e/HK9oPXfaM2IEHjkq03jIC/FcWn/QMtFjOUBqQU94rnqdivFdFkeZHk1WUQgC0hztH3Qhh9zu2PNIrYUDpVD5dJqBpprWbSwFP8yNsJlP9A2RUubTlZblKHuaBhhiuNN+kU=
-  - secure: gsAAl/RaTodLJDHWOuHZWtooa9/psyXBONF7ElZOTki3WvH+KugtjuXn3pXBGbUhvGqd5qfgPqX7WQOFP9KTdkXBbkU20rCHLh3SV8V2vRkGFAFiGPBTFfSA83zFNMvmgEnTww4OzYsfs4wHTEyxBeQkggnB5bXEvqkFVrHBjuQ=
-  - secure: mMa7UUt+CQDB52fGM1T3oRL67OzQzRIc+BQCOqUEUhBV7p5g7Y1Hv6NTdVZTvK16x3DsP+5kFNd1v7rsTFw2qzP3hOxIv2BtMPuSzZdnN85Zd/nGwnztxzj/rqw7TMBaYvIdEZZbpRF/K0p0Xr6LJK2s9UkPXPUaLqly7kNi360=
+    - secure: aswHU7pQroGM+GHoYlhXzzk2FYfqxXJORjqXPsbgoHAIu4Bssaj8+YAzIcdy3j9kSt4I8VBpjnn8H/wzQXki75JBZOosQrIeMK018+uR+ZMONBLqDYW/N7EJHLgZt9QXxQNKeZygrD4GN/Dc4gLHGvPQC/RfPuuHcnF0Liaahoo=
+    - secure: RZ6M6984P885GRoyx9n/WCCWGoFAzYpS8sZkXu3e/HK9oPXfaM2IEHjkq03jIC/FcWn/QMtFjOUBqQU94rnqdivFdFkeZHk1WUQgC0hztH3Qhh9zu2PNIrYUDpVD5dJqBpprWbSwFP8yNsJlP9A2RUubTlZblKHuaBhhiuNN+kU=
+    - secure: gsAAl/RaTodLJDHWOuHZWtooa9/psyXBONF7ElZOTki3WvH+KugtjuXn3pXBGbUhvGqd5qfgPqX7WQOFP9KTdkXBbkU20rCHLh3SV8V2vRkGFAFiGPBTFfSA83zFNMvmgEnTww4OzYsfs4wHTEyxBeQkggnB5bXEvqkFVrHBjuQ=
+    - secure: mMa7UUt+CQDB52fGM1T3oRL67OzQzRIc+BQCOqUEUhBV7p5g7Y1Hv6NTdVZTvK16x3DsP+5kFNd1v7rsTFw2qzP3hOxIv2BtMPuSzZdnN85Zd/nGwnztxzj/rqw7TMBaYvIdEZZbpRF/K0p0Xr6LJK2s9UkPXPUaLqly7kNi360=
 
 install:
   - pip install tox
 
 script:
-  # Update Python 3.6 path - see bug https://github.com/travis-ci/travis-ci/issues/4990
-  - if [[ $TOX_ENV = *"py36"* ]]; then echo "Activated PY3.6"; source ~/virtualenv/python3.6/bin/activate; pip install tox; fi
   - tox -e $TOX_ENV
-
-sudo: false
diff --git a/django_mailbox/admin.py b/django_mailbox/admin.py
index c586b40..e9a6ef7 100644
--- a/django_mailbox/admin.py
+++ b/django_mailbox/admin.py
@@ -1,5 +1,4 @@
 #!/usr/bin/env python
-# -*- coding: utf-8 -*-
 
 """
 Model configuration in application ``django_mailbox`` for administration
@@ -10,7 +9,7 @@ import logging
 
 from django.conf import settings
 from django.contrib import admin
-from django.utils.translation import ugettext_lazy as _
+from django.utils.translation import gettext_lazy as _
 
 from django_mailbox.models import MessageAttachment, Message, Mailbox
 from django_mailbox.signals import message_received
@@ -74,7 +73,7 @@ class MessageAdmin(admin.ModelAdmin):
     def envelope_headers(self, msg):
         email = msg.get_email_object()
         return '\n'.join(
-            [('%s: %s' % (h, v)) for h, v in email.items()]
+            [('{}: {}'.format(h, v)) for h, v in email.items()]
         )
 
     inlines = [
diff --git a/django_mailbox/apps.py b/django_mailbox/apps.py
index 87eb64b..13b7bf3 100644
--- a/django_mailbox/apps.py
+++ b/django_mailbox/apps.py
@@ -1,5 +1,5 @@
 from django.apps import AppConfig
-from django.utils.translation import ugettext_lazy as _
+from django.utils.translation import gettext_lazy as _
 
 
 class MailBoxConfig(AppConfig):
diff --git a/django_mailbox/migrations/0001_initial.py b/django_mailbox/migrations/0001_initial.py
index 0d27460..13bb802 100644
--- a/django_mailbox/migrations/0001_initial.py
+++ b/django_mailbox/migrations/0001_initial.py
@@ -1,6 +1,3 @@
-# -*- coding: utf-8 -*-
-from __future__ import unicode_literals
-
 from django.db import models, migrations
 
 
diff --git a/django_mailbox/migrations/0002_add_eml_to_message.py b/django_mailbox/migrations/0002_add_eml_to_message.py
index a78cfb4..4204efb 100644
--- a/django_mailbox/migrations/0002_add_eml_to_message.py
+++ b/django_mailbox/migrations/0002_add_eml_to_message.py
@@ -1,6 +1,3 @@
-# -*- coding: utf-8 -*-
-from __future__ import unicode_literals
-
 from django.db import models, migrations
 
 
diff --git a/django_mailbox/migrations/0003_auto_20150409_0316.py b/django_mailbox/migrations/0003_auto_20150409_0316.py
index 8c3fad9..1b5def0 100644
--- a/django_mailbox/migrations/0003_auto_20150409_0316.py
+++ b/django_mailbox/migrations/0003_auto_20150409_0316.py
@@ -1,6 +1,3 @@
-# -*- coding: utf-8 -*-
-from __future__ import unicode_literals
-
 from django.db import models, migrations
 
 
diff --git a/django_mailbox/migrations/0004_bytestring_to_unicode.py b/django_mailbox/migrations/0004_bytestring_to_unicode.py
index fedc46a..7716f2f 100644
--- a/django_mailbox/migrations/0004_bytestring_to_unicode.py
+++ b/django_mailbox/migrations/0004_bytestring_to_unicode.py
@@ -1,6 +1,3 @@
-# -*- coding: utf-8 -*-
-from __future__ import unicode_literals
-
 from django.db import models, migrations
 
 
diff --git a/django_mailbox/migrations/0005_auto_20160523_2240.py b/django_mailbox/migrations/0005_auto_20160523_2240.py
index a639a2c..f4bdae6 100644
--- a/django_mailbox/migrations/0005_auto_20160523_2240.py
+++ b/django_mailbox/migrations/0005_auto_20160523_2240.py
@@ -1,6 +1,3 @@
-# -*- coding: utf-8 -*-
-from __future__ import unicode_literals
-
 from django.db import migrations, models
 import django_mailbox.utils
 
diff --git a/django_mailbox/migrations/0006_mailbox_last_polling.py b/django_mailbox/migrations/0006_mailbox_last_polling.py
index 7979428..5f1524e 100644
--- a/django_mailbox/migrations/0006_mailbox_last_polling.py
+++ b/django_mailbox/migrations/0006_mailbox_last_polling.py
@@ -1,6 +1,4 @@
-# -*- coding: utf-8 -*-
 # Generated by Django 1.9.8 on 2016-08-15 22:39
-from __future__ import unicode_literals
 
 from django.db import migrations, models
 
diff --git a/django_mailbox/migrations/0007_auto_20180421_0026.py b/django_mailbox/migrations/0007_auto_20180421_0026.py
index 4195f70..2e984d0 100644
--- a/django_mailbox/migrations/0007_auto_20180421_0026.py
+++ b/django_mailbox/migrations/0007_auto_20180421_0026.py
@@ -1,6 +1,4 @@
-# -*- coding: utf-8 -*-
 # Generated by Django 1.10.7 on 2018-04-21 00:26
-from __future__ import unicode_literals
 
 from django.db import migrations
 
diff --git a/django_mailbox/models.py b/django_mailbox/models.py
index 9f7ffc2..4e5b111 100644
--- a/django_mailbox/models.py
+++ b/django_mailbox/models.py
@@ -1,5 +1,4 @@
 #!/usr/bin/env python
-# -*- coding: utf-8 -*-
 
 """
 Models declaration for application ``django_mailbox``.
@@ -8,7 +7,9 @@ import gzip
 from email.encoders import encode_base64
 from email.message import Message as EmailMessage
 from email.utils import formatdate, parseaddr
+from urllib.parse import parse_qs, unquote, urlparse
 from quopri import encode as encode_quopri
+from io import BytesIO
 import base64
 import email
 import logging
@@ -18,17 +19,13 @@ import sys
 import uuid
 from tempfile import NamedTemporaryFile
 
-import six
-from six.moves.urllib.parse import parse_qs, unquote, urlparse
-
 import django
 from django.conf import settings as django_settings
 from django.core.files.base import ContentFile, File
 from django.core.mail.message import make_msgid
 from django.db import models
-from django.utils.translation import ugettext_lazy as _
+from django.utils.translation import gettext_lazy as _
 from django.utils.timezone import now
-from django.utils.encoding import python_2_unicode_compatible
 
 from django_mailbox import utils
 from django_mailbox.signals import message_received
@@ -41,20 +38,19 @@ logger = logging.getLogger(__name__)
 
 class ActiveMailboxManager(models.Manager):
     def get_queryset(self):
-        return super(ActiveMailboxManager, self).get_queryset().filter(
+        return super().get_queryset().filter(
             active=True,
         )
 
 
-@python_2_unicode_compatible
 class Mailbox(models.Model):
     name = models.CharField(
-        _(u'Name'),
+        _('Name'),
         max_length=255,
     )
 
     uri = models.CharField(
-        _(u'URI'),
+        _('URI'),
         max_length=255,
         help_text=(_(
             "Example: imap+ssl://myusername:mypassword@someserver <br />"
@@ -72,7 +68,7 @@ class Mailbox(models.Model):
     )
 
     from_email = models.CharField(
-        _(u'From email'),
+        _('From email'),
         max_length=255,
         help_text=(_(
             "Example: MailBot &lt;mailbot@yourdomain.com&gt;<br />"
@@ -89,7 +85,7 @@ class Mailbox(models.Model):
     )
 
     active = models.BooleanField(
-        _(u'Active'),
+        _('Active'),
         help_text=(_(
             "Check this e-mail inbox for new e-mail messages during polling "
             "cycles.  This checkbox does not have an effect upon whether "
@@ -102,7 +98,7 @@ class Mailbox(models.Model):
     )
 
     last_polling = models.DateTimeField(
-        _(u"Last polling"),
+        _("Last polling"),
         help_text=(_("The time of last successful polling for messages."
                      "It is blank for new mailboxes and is not set for "
                      "mailboxes that only receive messages via a pipe.")),
@@ -294,7 +290,7 @@ class Mailbox(models.Model):
             attachment.document.save(
                 uuid.uuid4().hex + extension,
                 ContentFile(
-                    six.BytesIO(
+                    BytesIO(
                         msg.get_payload(decode=True)
                     ).getvalue()
                 )
@@ -392,7 +388,7 @@ class Mailbox(models.Model):
                 with gzip.GzipFile(fileobj=fp_tmp, mode="w") as fp:
                     fp.write(message.as_string().encode('utf-8'))
                 msg.eml.save(
-                    "%s.eml.gz" % (uuid.uuid4(), ),
+                    "{}.eml.gz".format(uuid.uuid4()),
                     File(fp_tmp),
                     save=False
                 )
@@ -430,41 +426,40 @@ class Mailbox(models.Model):
 
 class IncomingMessageManager(models.Manager):
     def get_queryset(self):
-        return super(IncomingMessageManager, self).get_queryset().filter(
+        return super().get_queryset().filter(
             outgoing=False,
         )
 
 
 class OutgoingMessageManager(models.Manager):
     def get_queryset(self):
-        return super(OutgoingMessageManager, self).get_queryset().filter(
+        return super().get_queryset().filter(
             outgoing=True,
         )
 
 
 class UnreadMessageManager(models.Manager):
     def get_queryset(self):
-        return super(UnreadMessageManager, self).get_queryset().filter(
+        return super().get_queryset().filter(
             read=None
         )
 
 
-@python_2_unicode_compatible
 class Message(models.Model):
     mailbox = models.ForeignKey(
         Mailbox,
         related_name='messages',
-        verbose_name=_(u'Mailbox'),
+        verbose_name=_('Mailbox'),
         on_delete=models.CASCADE
     )
 
     subject = models.CharField(
-        _(u'Subject'),
+        _('Subject'),
         max_length=255
     )
 
     message_id = models.CharField(
-        _(u'Message ID'),
+        _('Message ID'),
         max_length=255
     )
 
@@ -473,7 +468,7 @@ class Message(models.Model):
         related_name='replies',
         blank=True,
         null=True,
-        verbose_name=_(u'In reply to'),
+        verbose_name=_('In reply to'),
         on_delete=models.CASCADE
     )
 
@@ -483,21 +478,21 @@ class Message(models.Model):
     )
 
     to_header = models.TextField(
-        _(u'To header'),
+        _('To header'),
     )
 
     outgoing = models.BooleanField(
-        _(u'Outgoing'),
+        _('Outgoing'),
         default=False,
         blank=True,
     )
 
     body = models.TextField(
-        _(u'Body'),
+        _('Body'),
     )
 
     encoded = models.BooleanField(
-        _(u'Encoded'),
+        _('Encoded'),
         default=False,
         help_text=_('True if the e-mail body is Base64 encoded'),
     )
@@ -508,17 +503,17 @@ class Message(models.Model):
     )
 
     read = models.DateTimeField(
-        _(u'Read'),
+        _('Read'),
         default=None,
         blank=True,
         null=True,
     )
 
     eml = models.FileField(
-        _(u'Raw message contents'),
+        _('Raw message contents'),
         null=True,
         upload_to="messages",
-        help_text=_(u'Original full content of message')
+        help_text=_('Original full content of message')
     )
     objects = models.Manager()
     unread_messages = UnreadMessageManager()
@@ -634,9 +629,9 @@ class Message(models.Model):
                 if encoding and encoding.lower() == 'quoted-printable':
                     # Cannot use `email.encoders.encode_quopri due to
                     # bug 14360: http://bugs.python.org/issue14360
-                    output = six.BytesIO()
+                    output = BytesIO()
                     encode_quopri(
-                        six.BytesIO(
+                        BytesIO(
                             attachment.document.read()
                         ),
                         output,
@@ -688,10 +683,8 @@ class Message(models.Model):
         no fields existed for storing arbitrary bytes.
 
         """
-        if six.PY3:
-            body = body.encode('utf-8')
         self.encoded = True
-        self.body = base64.b64encode(body).decode('ascii')
+        self.body = base64.b64encode(body.encode('utf-8')).decode('ascii')
 
     def get_email_object(self):
         """Returns an `email.message.Message` instance representing the
@@ -722,10 +715,7 @@ class Message(models.Model):
                     self.eml.close()
             else:
                 body = self.get_body()
-            if six.PY3:
-                flat = email.message_from_bytes(body)
-            else:
-                flat = email.message_from_string(body)
+            flat = email.message_from_bytes(body)
             self._email_object = self._rehydrate(flat)
         return self._email_object
 
@@ -734,7 +724,7 @@ class Message(models.Model):
         for attachment in self.attachments.all():
             # This attachment is attached only to this message.
             attachment.delete()
-        return super(Message, self).delete(*args, **kwargs)
+        return super().delete(*args, **kwargs)
 
     def __str__(self):
         return self.subject
@@ -744,7 +734,6 @@ class Message(models.Model):
         verbose_name_plural = _('E-mail messages')
 
 
-@python_2_unicode_compatible
 class MessageAttachment(models.Model):
     message = models.ForeignKey(
         Message,
@@ -756,30 +745,25 @@ class MessageAttachment(models.Model):
     )
 
     headers = models.TextField(
-        _(u'Headers'),
+        _('Headers'),
         null=True,
         blank=True,
     )
 
     document = models.FileField(
-        _(u'Document'),
+        _('Document'),
         upload_to=utils.get_attachment_save_path,
     )
 
     def delete(self, *args, **kwargs):
         """Deletes the attachment."""
         self.document.delete()
-        return super(MessageAttachment, self).delete(*args, **kwargs)
+        return super().delete(*args, **kwargs)
 
     def _get_rehydrated_headers(self):
         headers = self.headers
         if headers is None:
             return EmailMessage()
-        if sys.version_info < (3, 0):
-            try:
-                headers = headers.encode('utf-8')
-            except UnicodeDecodeError:
-                headers = headers.decode('utf-8').encode('utf-8')
         return email.message_from_string(headers)
 
     def _set_dehydrated_headers(self, email_object):
@@ -798,7 +782,7 @@ class MessageAttachment(models.Model):
     def get_filename(self):
         """Returns the original filename of this attachment."""
         file_name = self._get_rehydrated_headers().get_filename()
-        if isinstance(file_name, six.string_types):
+        if isinstance(file_name, str):
             result = utils.convert_header_to_unicode(file_name)
             if result is None:
                 return file_name
diff --git a/django_mailbox/south_migrations/0001_initial.py b/django_mailbox/south_migrations/0001_initial.py
index 4faa4fa..dcfdf60 100644
--- a/django_mailbox/south_migrations/0001_initial.py
+++ b/django_mailbox/south_migrations/0001_initial.py
@@ -1,4 +1,3 @@
-# -*- coding: utf-8 -*-
 import datetime
 from south.db import db
 from south.v2 import SchemaMigration
diff --git a/django_mailbox/south_migrations/0002_auto__chg_field_mailbox_uri.py b/django_mailbox/south_migrations/0002_auto__chg_field_mailbox_uri.py
index 3ff3098..47517b3 100644
--- a/django_mailbox/south_migrations/0002_auto__chg_field_mailbox_uri.py
+++ b/django_mailbox/south_migrations/0002_auto__chg_field_mailbox_uri.py
@@ -1,4 +1,3 @@
-# -*- coding: utf-8 -*-
 import datetime
 from south.db import db
 from south.v2 import SchemaMigration
diff --git a/django_mailbox/south_migrations/0003_auto__add_field_mailbox_active.py b/django_mailbox/south_migrations/0003_auto__add_field_mailbox_active.py
index a067e50..30e4354 100644
--- a/django_mailbox/south_migrations/0003_auto__add_field_mailbox_active.py
+++ b/django_mailbox/south_migrations/0003_auto__add_field_mailbox_active.py
@@ -1,4 +1,3 @@
-# -*- coding: utf-8 -*-
 import datetime
 from south.db import db
 from south.v2 import SchemaMigration
diff --git a/django_mailbox/south_migrations/0004_auto__add_field_message_outgoing.py b/django_mailbox/south_migrations/0004_auto__add_field_message_outgoing.py
index 20e889a..245c43b 100644
--- a/django_mailbox/south_migrations/0004_auto__add_field_message_outgoing.py
+++ b/django_mailbox/south_migrations/0004_auto__add_field_message_outgoing.py
@@ -1,4 +1,3 @@
-# -*- coding: utf-8 -*-
 import datetime
 from south.db import db
 from south.v2 import SchemaMigration
diff --git a/django_mailbox/south_migrations/0005_rename_fields.py b/django_mailbox/south_migrations/0005_rename_fields.py
index 35bc858..72cb437 100644
--- a/django_mailbox/south_migrations/0005_rename_fields.py
+++ b/django_mailbox/south_migrations/0005_rename_fields.py
@@ -1,4 +1,3 @@
-# -*- coding: utf-8 -*-
 import datetime
 from south.db import db
 from south.v2 import SchemaMigration
diff --git a/django_mailbox/south_migrations/0006_auto__add_field_message_in_reply_to.py b/django_mailbox/south_migrations/0006_auto__add_field_message_in_reply_to.py
index 7c8b9d7..4287fb2 100644
--- a/django_mailbox/south_migrations/0006_auto__add_field_message_in_reply_to.py
+++ b/django_mailbox/south_migrations/0006_auto__add_field_message_in_reply_to.py
@@ -1,4 +1,3 @@
-# -*- coding: utf-8 -*-
 import datetime
 from south.db import db
 from south.v2 import SchemaMigration
diff --git a/django_mailbox/south_migrations/0007_auto__del_field_message_address__add_field_message_from_header__add_fi.py b/django_mailbox/south_migrations/0007_auto__del_field_message_address__add_field_message_from_header__add_fi.py
index 150e53e..cfa7d6f 100644
--- a/django_mailbox/south_migrations/0007_auto__del_field_message_address__add_field_message_from_header__add_fi.py
+++ b/django_mailbox/south_migrations/0007_auto__del_field_message_address__add_field_message_from_header__add_fi.py
@@ -1,4 +1,3 @@
-# -*- coding: utf-8 -*-
 import datetime
 from south.db import db
 from south.v2 import SchemaMigration
diff --git a/django_mailbox/south_migrations/0008_populate_from_to_fields.py b/django_mailbox/south_migrations/0008_populate_from_to_fields.py
index 68de935..e047f22 100644
--- a/django_mailbox/south_migrations/0008_populate_from_to_fields.py
+++ b/django_mailbox/south_migrations/0008_populate_from_to_fields.py
@@ -1,4 +1,3 @@
-# -*- coding: utf-8 -*-
 import datetime
 import email
 from south.db import db
diff --git a/django_mailbox/south_migrations/0009_remove_references_table.py b/django_mailbox/south_migrations/0009_remove_references_table.py
index 38afc96..3868585 100644
--- a/django_mailbox/south_migrations/0009_remove_references_table.py
+++ b/django_mailbox/south_migrations/0009_remove_references_table.py
@@ -1,4 +1,3 @@
-# -*- coding: utf-8 -*-
 import datetime
 from south.db import db
 from south.v2 import SchemaMigration
diff --git a/django_mailbox/south_migrations/0010_auto__add_field_mailbox_from_email.py b/django_mailbox/south_migrations/0010_auto__add_field_mailbox_from_email.py
index 9261e6d..a988e5e 100644
--- a/django_mailbox/south_migrations/0010_auto__add_field_mailbox_from_email.py
+++ b/django_mailbox/south_migrations/0010_auto__add_field_mailbox_from_email.py
@@ -1,4 +1,3 @@
-# -*- coding: utf-8 -*-
 import datetime
 from south.db import db
 from south.v2 import SchemaMigration
diff --git a/django_mailbox/south_migrations/0011_auto__add_field_message_read.py b/django_mailbox/south_migrations/0011_auto__add_field_message_read.py
index b288170..c75db34 100644
--- a/django_mailbox/south_migrations/0011_auto__add_field_message_read.py
+++ b/django_mailbox/south_migrations/0011_auto__add_field_message_read.py
@@ -1,4 +1,3 @@
-# -*- coding: utf-8 -*-
 import datetime
 from south.db import db
 from south.v2 import SchemaMigration
diff --git a/django_mailbox/south_migrations/0012_auto__add_messageattachment.py b/django_mailbox/south_migrations/0012_auto__add_messageattachment.py
index 554483e..b62e50e 100644
--- a/django_mailbox/south_migrations/0012_auto__add_messageattachment.py
+++ b/django_mailbox/south_migrations/0012_auto__add_messageattachment.py
@@ -1,4 +1,3 @@
-# encoding: utf-8
 import datetime
 from south.db import db
 from south.v2 import SchemaMigration
diff --git a/django_mailbox/south_migrations/0013_auto__add_field_messageattachment_message.py b/django_mailbox/south_migrations/0013_auto__add_field_messageattachment_message.py
index d1b9b0d..01c80a2 100644
--- a/django_mailbox/south_migrations/0013_auto__add_field_messageattachment_message.py
+++ b/django_mailbox/south_migrations/0013_auto__add_field_messageattachment_message.py
@@ -1,4 +1,3 @@
-# -*- coding: utf-8 -*-
 import datetime
 from south.db import db
 from south.v2 import SchemaMigration
@@ -9,33 +8,33 @@ class Migration(SchemaMigration):
 
     def forwards(self, orm):
         # Adding field 'MessageAttachment.message'
-        db.add_column(u'django_mailbox_messageattachment', 'message',
+        db.add_column('django_mailbox_messageattachment', 'message',
                       self.gf('django.db.models.fields.related.ForeignKey')(blank=True, related_name='attachments', null=True, to=orm['django_mailbox.Message']),
                       keep_default=False)
 
 
     def backwards(self, orm):
         # Deleting field 'MessageAttachment.message'
-        db.delete_column(u'django_mailbox_messageattachment', 'message_id')
+        db.delete_column('django_mailbox_messageattachment', 'message_id')
 
 
     models = {
-        u'django_mailbox.mailbox': {
+        'django_mailbox.mailbox': {
             'Meta': {'object_name': 'Mailbox'},
             'active': ('django.db.models.fields.BooleanField', [], {'default': 'True'}),
             'from_email': ('django.db.models.fields.CharField', [], {'default': 'None', 'max_length': '255', 'null': 'True', 'blank': 'True'}),
-            u'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
             'name': ('django.db.models.fields.CharField', [], {'max_length': '255'}),
             'uri': ('django.db.models.fields.CharField', [], {'default': 'None', 'max_length': '255', 'null': 'True', 'blank': 'True'})
         },
-        u'django_mailbox.message': {
+        'django_mailbox.message': {
             'Meta': {'object_name': 'Message'},
-            'attachments': ('django.db.models.fields.related.ManyToManyField', [], {'symmetrical': 'False', 'related_name': "'messages_old'", 'blank': 'True', 'to': u"orm['django_mailbox.MessageAttachment']"}),
+            'attachments': ('django.db.models.fields.related.ManyToManyField', [], {'symmetrical': 'False', 'related_name': "'messages_old'", 'blank': 'True', 'to': "orm['django_mailbox.MessageAttachment']"}),
             'body': ('django.db.models.fields.TextField', [], {}),
             'from_header': ('django.db.models.fields.CharField', [], {'max_length': '255'}),
-            u'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
-            'in_reply_to': ('django.db.models.fields.related.ForeignKey', [], {'blank': 'True', 'related_name': "'replies'", 'null': 'True', 'to': u"orm['django_mailbox.Message']"}),
-            'mailbox': ('django.db.models.fields.related.ForeignKey', [], {'related_name': "'messages'", 'to': u"orm['django_mailbox.Mailbox']"}),
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'in_reply_to': ('django.db.models.fields.related.ForeignKey', [], {'blank': 'True', 'related_name': "'replies'", 'null': 'True', 'to': "orm['django_mailbox.Message']"}),
+            'mailbox': ('django.db.models.fields.related.ForeignKey', [], {'related_name': "'messages'", 'to': "orm['django_mailbox.Mailbox']"}),
             'message_id': ('django.db.models.fields.CharField', [], {'max_length': '255'}),
             'outgoing': ('django.db.models.fields.BooleanField', [], {'default': 'False'}),
             'processed': ('django.db.models.fields.DateTimeField', [], {'auto_now_add': 'True', 'blank': 'True'}),
@@ -43,11 +42,11 @@ class Migration(SchemaMigration):
             'subject': ('django.db.models.fields.CharField', [], {'max_length': '255'}),
             'to_header': ('django.db.models.fields.TextField', [], {})
         },
-        u'django_mailbox.messageattachment': {
+        'django_mailbox.messageattachment': {
             'Meta': {'object_name': 'MessageAttachment'},
             'document': ('django.db.models.fields.files.FileField', [], {'max_length': '100'}),
-            u'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
-            'message': ('django.db.models.fields.related.ForeignKey', [], {'blank': 'True', 'related_name': "'attachments_new'", 'null': 'True', 'to': u"orm['django_mailbox.Message']"})
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'message': ('django.db.models.fields.related.ForeignKey', [], {'blank': 'True', 'related_name': "'attachments_new'", 'null': 'True', 'to': "orm['django_mailbox.Message']"})
         }
     }
 
diff --git a/django_mailbox/south_migrations/0014_migrate_message_attachments.py b/django_mailbox/south_migrations/0014_migrate_message_attachments.py
index a4fff5d..b018915 100644
--- a/django_mailbox/south_migrations/0014_migrate_message_attachments.py
+++ b/django_mailbox/south_migrations/0014_migrate_message_attachments.py
@@ -1,4 +1,3 @@
-# -*- coding: utf-8 -*-
 import datetime
 from south.db import db
 from south.v2 import SchemaMigration
@@ -21,22 +20,22 @@ class Migration(SchemaMigration):
                 )
 
     models = {
-        u'django_mailbox.mailbox': {
+        'django_mailbox.mailbox': {
             'Meta': {'object_name': 'Mailbox'},
             'active': ('django.db.models.fields.BooleanField', [], {'default': 'True'}),
             'from_email': ('django.db.models.fields.CharField', [], {'default': 'None', 'max_length': '255', 'null': 'True', 'blank': 'True'}),
-            u'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
             'name': ('django.db.models.fields.CharField', [], {'max_length': '255'}),
             'uri': ('django.db.models.fields.CharField', [], {'default': 'None', 'max_length': '255', 'null': 'True', 'blank': 'True'})
         },
-        u'django_mailbox.message': {
+        'django_mailbox.message': {
             'Meta': {'object_name': 'Message'},
-            'attachments': ('django.db.models.fields.related.ManyToManyField', [], {'symmetrical': 'False', 'related_name': "'messages_old'", 'blank': 'True', 'to': u"orm['django_mailbox.MessageAttachment']"}),
+            'attachments': ('django.db.models.fields.related.ManyToManyField', [], {'symmetrical': 'False', 'related_name': "'messages_old'", 'blank': 'True', 'to': "orm['django_mailbox.MessageAttachment']"}),
             'body': ('django.db.models.fields.TextField', [], {}),
             'from_header': ('django.db.models.fields.CharField', [], {'max_length': '255'}),
-            u'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
-            'in_reply_to': ('django.db.models.fields.related.ForeignKey', [], {'blank': 'True', 'related_name': "'replies'", 'null': 'True', 'to': u"orm['django_mailbox.Message']"}),
-            'mailbox': ('django.db.models.fields.related.ForeignKey', [], {'related_name': "'messages'", 'to': u"orm['django_mailbox.Mailbox']"}),
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'in_reply_to': ('django.db.models.fields.related.ForeignKey', [], {'blank': 'True', 'related_name': "'replies'", 'null': 'True', 'to': "orm['django_mailbox.Message']"}),
+            'mailbox': ('django.db.models.fields.related.ForeignKey', [], {'related_name': "'messages'", 'to': "orm['django_mailbox.Mailbox']"}),
             'message_id': ('django.db.models.fields.CharField', [], {'max_length': '255'}),
             'outgoing': ('django.db.models.fields.BooleanField', [], {'default': 'False'}),
             'processed': ('django.db.models.fields.DateTimeField', [], {'auto_now_add': 'True', 'blank': 'True'}),
@@ -44,11 +43,11 @@ class Migration(SchemaMigration):
             'subject': ('django.db.models.fields.CharField', [], {'max_length': '255'}),
             'to_header': ('django.db.models.fields.TextField', [], {})
         },
-        u'django_mailbox.messageattachment': {
+        'django_mailbox.messageattachment': {
             'Meta': {'object_name': 'MessageAttachment'},
             'document': ('django.db.models.fields.files.FileField', [], {'max_length': '100'}),
-            u'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
-            'message': ('django.db.models.fields.related.ForeignKey', [], {'blank': 'True', 'related_name': "'attachments_new'", 'null': 'True', 'to': u"orm['django_mailbox.Message']"})
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'message': ('django.db.models.fields.related.ForeignKey', [], {'blank': 'True', 'related_name': "'attachments_new'", 'null': 'True', 'to': "orm['django_mailbox.Message']"})
         }
     }
 
diff --git a/django_mailbox/south_migrations/0015_auto__add_field_messageattachment_headers.py b/django_mailbox/south_migrations/0015_auto__add_field_messageattachment_headers.py
index 7531244..71ecfbd 100644
--- a/django_mailbox/south_migrations/0015_auto__add_field_messageattachment_headers.py
+++ b/django_mailbox/south_migrations/0015_auto__add_field_messageattachment_headers.py
@@ -1,4 +1,3 @@
-# -*- coding: utf-8 -*-
 import datetime
 from south.db import db
 from south.v2 import SchemaMigration
@@ -12,40 +11,40 @@ class Migration(SchemaMigration):
         db.delete_table('django_mailbox_message_attachments')
 
         # Adding field 'MessageAttachment.headers'
-        db.add_column(u'django_mailbox_messageattachment', 'headers',
+        db.add_column('django_mailbox_messageattachment', 'headers',
                       self.gf('django.db.models.fields.TextField')(null=True, blank=True),
                       keep_default=False)
 
 
     def backwards(self, orm):
         # Adding M2M table for field attachments on 'Message'
-        db.create_table(u'django_mailbox_message_attachments', (
+        db.create_table('django_mailbox_message_attachments', (
             ('id', models.AutoField(verbose_name='ID', primary_key=True, auto_created=True)),
-            ('message', models.ForeignKey(orm[u'django_mailbox.message'], null=False)),
-            ('messageattachment', models.ForeignKey(orm[u'django_mailbox.messageattachment'], null=False))
+            ('message', models.ForeignKey(orm['django_mailbox.message'], null=False)),
+            ('messageattachment', models.ForeignKey(orm['django_mailbox.messageattachment'], null=False))
         ))
-        db.create_unique(u'django_mailbox_message_attachments', ['message_id', 'messageattachment_id'])
+        db.create_unique('django_mailbox_message_attachments', ['message_id', 'messageattachment_id'])
 
         # Deleting field 'MessageAttachment.headers'
-        db.delete_column(u'django_mailbox_messageattachment', 'headers')
+        db.delete_column('django_mailbox_messageattachment', 'headers')
 
 
     models = {
-        u'django_mailbox.mailbox': {
+        'django_mailbox.mailbox': {
             'Meta': {'object_name': 'Mailbox'},
             'active': ('django.db.models.fields.BooleanField', [], {'default': 'True'}),
             'from_email': ('django.db.models.fields.CharField', [], {'default': 'None', 'max_length': '255', 'null': 'True', 'blank': 'True'}),
-            u'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
             'name': ('django.db.models.fields.CharField', [], {'max_length': '255'}),
             'uri': ('django.db.models.fields.CharField', [], {'default': 'None', 'max_length': '255', 'null': 'True', 'blank': 'True'})
         },
-        u'django_mailbox.message': {
+        'django_mailbox.message': {
             'Meta': {'object_name': 'Message'},
             'body': ('django.db.models.fields.TextField', [], {}),
             'from_header': ('django.db.models.fields.CharField', [], {'max_length': '255'}),
-            u'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
-            'in_reply_to': ('django.db.models.fields.related.ForeignKey', [], {'blank': 'True', 'related_name': "'replies'", 'null': 'True', 'to': u"orm['django_mailbox.Message']"}),
-            'mailbox': ('django.db.models.fields.related.ForeignKey', [], {'related_name': "'messages'", 'to': u"orm['django_mailbox.Mailbox']"}),
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'in_reply_to': ('django.db.models.fields.related.ForeignKey', [], {'blank': 'True', 'related_name': "'replies'", 'null': 'True', 'to': "orm['django_mailbox.Message']"}),
+            'mailbox': ('django.db.models.fields.related.ForeignKey', [], {'related_name': "'messages'", 'to': "orm['django_mailbox.Mailbox']"}),
             'message_id': ('django.db.models.fields.CharField', [], {'max_length': '255'}),
             'outgoing': ('django.db.models.fields.BooleanField', [], {'default': 'False'}),
             'processed': ('django.db.models.fields.DateTimeField', [], {'auto_now_add': 'True', 'blank': 'True'}),
@@ -53,12 +52,12 @@ class Migration(SchemaMigration):
             'subject': ('django.db.models.fields.CharField', [], {'max_length': '255'}),
             'to_header': ('django.db.models.fields.TextField', [], {})
         },
-        u'django_mailbox.messageattachment': {
+        'django_mailbox.messageattachment': {
             'Meta': {'object_name': 'MessageAttachment'},
             'document': ('django.db.models.fields.files.FileField', [], {'max_length': '100'}),
             'headers': ('django.db.models.fields.TextField', [], {'null': 'True', 'blank': 'True'}),
-            u'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
-            'message': ('django.db.models.fields.related.ForeignKey', [], {'blank': 'True', 'related_name': "'attachments'", 'null': 'True', 'to': u"orm['django_mailbox.Message']"})
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'message': ('django.db.models.fields.related.ForeignKey', [], {'blank': 'True', 'related_name': "'attachments'", 'null': 'True', 'to': "orm['django_mailbox.Message']"})
         }
     }
 
diff --git a/django_mailbox/south_migrations/0016_auto__add_field_message_encoded.py b/django_mailbox/south_migrations/0016_auto__add_field_message_encoded.py
index 8fa5e9d..cd4c678 100644
--- a/django_mailbox/south_migrations/0016_auto__add_field_message_encoded.py
+++ b/django_mailbox/south_migrations/0016_auto__add_field_message_encoded.py
@@ -1,4 +1,3 @@
-# -*- coding: utf-8 -*-
 import datetime
 from south.db import db
 from south.v2 import SchemaMigration
@@ -9,33 +8,33 @@ class Migration(SchemaMigration):
 
     def forwards(self, orm):
         # Adding field 'Message.encoded'
-        db.add_column(u'django_mailbox_message', 'encoded',
+        db.add_column('django_mailbox_message', 'encoded',
                       self.gf('django.db.models.fields.BooleanField')(default=False),
                       keep_default=False)
 
 
     def backwards(self, orm):
         # Deleting field 'Message.encoded'
-        db.delete_column(u'django_mailbox_message', 'encoded')
+        db.delete_column('django_mailbox_message', 'encoded')
 
 
     models = {
-        u'django_mailbox.mailbox': {
+        'django_mailbox.mailbox': {
             'Meta': {'object_name': 'Mailbox'},
             'active': ('django.db.models.fields.BooleanField', [], {'default': 'True'}),
             'from_email': ('django.db.models.fields.CharField', [], {'default': 'None', 'max_length': '255', 'null': 'True', 'blank': 'True'}),
-            u'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
             'name': ('django.db.models.fields.CharField', [], {'max_length': '255'}),
             'uri': ('django.db.models.fields.CharField', [], {'default': 'None', 'max_length': '255', 'null': 'True', 'blank': 'True'})
         },
-        u'django_mailbox.message': {
+        'django_mailbox.message': {
             'Meta': {'object_name': 'Message'},
             'body': ('django.db.models.fields.TextField', [], {}),
             'encoded': ('django.db.models.fields.BooleanField', [], {'default': 'False'}),
             'from_header': ('django.db.models.fields.CharField', [], {'max_length': '255'}),
-            u'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
-            'in_reply_to': ('django.db.models.fields.related.ForeignKey', [], {'blank': 'True', 'related_name': "'replies'", 'null': 'True', 'to': u"orm['django_mailbox.Message']"}),
-            'mailbox': ('django.db.models.fields.related.ForeignKey', [], {'related_name': "'messages'", 'to': u"orm['django_mailbox.Mailbox']"}),
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'in_reply_to': ('django.db.models.fields.related.ForeignKey', [], {'blank': 'True', 'related_name': "'replies'", 'null': 'True', 'to': "orm['django_mailbox.Message']"}),
+            'mailbox': ('django.db.models.fields.related.ForeignKey', [], {'related_name': "'messages'", 'to': "orm['django_mailbox.Mailbox']"}),
             'message_id': ('django.db.models.fields.CharField', [], {'max_length': '255'}),
             'outgoing': ('django.db.models.fields.BooleanField', [], {'default': 'False'}),
             'processed': ('django.db.models.fields.DateTimeField', [], {'auto_now_add': 'True', 'blank': 'True'}),
@@ -43,12 +42,12 @@ class Migration(SchemaMigration):
             'subject': ('django.db.models.fields.CharField', [], {'max_length': '255'}),
             'to_header': ('django.db.models.fields.TextField', [], {})
         },
-        u'django_mailbox.messageattachment': {
+        'django_mailbox.messageattachment': {
             'Meta': {'object_name': 'MessageAttachment'},
             'document': ('django.db.models.fields.files.FileField', [], {'max_length': '100'}),
             'headers': ('django.db.models.fields.TextField', [], {'null': 'True', 'blank': 'True'}),
-            u'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
-            'message': ('django.db.models.fields.related.ForeignKey', [], {'blank': 'True', 'related_name': "'attachments'", 'null': 'True', 'to': u"orm['django_mailbox.Message']"})
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'message': ('django.db.models.fields.related.ForeignKey', [], {'blank': 'True', 'related_name': "'attachments'", 'null': 'True', 'to': "orm['django_mailbox.Message']"})
         }
     }
 
diff --git a/django_mailbox/south_migrations/0017_auto__add_field_message_eml.py b/django_mailbox/south_migrations/0017_auto__add_field_message_eml.py
index 9762908..186c8bd 100644
--- a/django_mailbox/south_migrations/0017_auto__add_field_message_eml.py
+++ b/django_mailbox/south_migrations/0017_auto__add_field_message_eml.py
@@ -1,4 +1,3 @@
-# -*- coding: utf-8 -*-
 from south.utils import datetime_utils as datetime
 from south.db import db
 from south.v2 import SchemaMigration
@@ -9,34 +8,34 @@ class Migration(SchemaMigration):
 
     def forwards(self, orm):
         # Adding field 'Message.eml'
-        db.add_column(u'django_mailbox_message', 'eml',
+        db.add_column('django_mailbox_message', 'eml',
                       self.gf('django.db.models.fields.files.FileField')(max_length=100, null=True),
                       keep_default=False)
 
 
     def backwards(self, orm):
         # Deleting field 'Message.eml'
-        db.delete_column(u'django_mailbox_message', 'eml')
+        db.delete_column('django_mailbox_message', 'eml')
 
 
     models = {
-        u'django_mailbox.mailbox': {
+        'django_mailbox.mailbox': {
             'Meta': {'object_name': 'Mailbox'},
             'active': ('django.db.models.fields.BooleanField', [], {'default': 'True'}),
             'from_email': ('django.db.models.fields.CharField', [], {'default': 'None', 'max_length': '255', 'null': 'True', 'blank': 'True'}),
-            u'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
             'name': ('django.db.models.fields.CharField', [], {'max_length': '255'}),
             'uri': ('django.db.models.fields.CharField', [], {'default': 'None', 'max_length': '255', 'null': 'True', 'blank': 'True'})
         },
-        u'django_mailbox.message': {
+        'django_mailbox.message': {
             'Meta': {'object_name': 'Message'},
             'body': ('django.db.models.fields.TextField', [], {}),
             'eml': ('django.db.models.fields.files.FileField', [], {'max_length': '100', 'null': 'True'}),
             'encoded': ('django.db.models.fields.BooleanField', [], {'default': 'False'}),
             'from_header': ('django.db.models.fields.CharField', [], {'max_length': '255'}),
-            u'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
-            'in_reply_to': ('django.db.models.fields.related.ForeignKey', [], {'blank': 'True', 'related_name': "'replies'", 'null': 'True', 'to': u"orm['django_mailbox.Message']"}),
-            'mailbox': ('django.db.models.fields.related.ForeignKey', [], {'related_name': "'messages'", 'to': u"orm['django_mailbox.Mailbox']"}),
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'in_reply_to': ('django.db.models.fields.related.ForeignKey', [], {'blank': 'True', 'related_name': "'replies'", 'null': 'True', 'to': "orm['django_mailbox.Message']"}),
+            'mailbox': ('django.db.models.fields.related.ForeignKey', [], {'related_name': "'messages'", 'to': "orm['django_mailbox.Mailbox']"}),
             'message_id': ('django.db.models.fields.CharField', [], {'max_length': '255'}),
             'outgoing': ('django.db.models.fields.BooleanField', [], {'default': 'False'}),
             'processed': ('django.db.models.fields.DateTimeField', [], {'auto_now_add': 'True', 'blank': 'True'}),
@@ -44,12 +43,12 @@ class Migration(SchemaMigration):
             'subject': ('django.db.models.fields.CharField', [], {'max_length': '255'}),
             'to_header': ('django.db.models.fields.TextField', [], {})
         },
-        u'django_mailbox.messageattachment': {
+        'django_mailbox.messageattachment': {
             'Meta': {'object_name': 'MessageAttachment'},
             'document': ('django.db.models.fields.files.FileField', [], {'max_length': '100'}),
             'headers': ('django.db.models.fields.TextField', [], {'null': 'True', 'blank': 'True'}),
-            u'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
-            'message': ('django.db.models.fields.related.ForeignKey', [], {'blank': 'True', 'related_name': "'attachments'", 'null': 'True', 'to': u"orm['django_mailbox.Message']"})
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'message': ('django.db.models.fields.related.ForeignKey', [], {'blank': 'True', 'related_name': "'attachments'", 'null': 'True', 'to': "orm['django_mailbox.Message']"})
         }
     }
 
diff --git a/django_mailbox/tests/base.py b/django_mailbox/tests/base.py
index 4884765..b1215c5 100644
--- a/django_mailbox/tests/base.py
+++ b/django_mailbox/tests/base.py
@@ -2,8 +2,6 @@ import email
 import os.path
 import time
 
-import six
-
 from django.conf import settings
 from django.test import TestCase
 
@@ -57,7 +55,7 @@ class EmailMessageTestCase(TestCase):
         settings.EMAIL_HOST_USER = self.test_account
         settings.EMAIL_HOST_PASSWORD = self.test_password
         settings.EMAIL_USE_TLS = True
-        super(EmailMessageTestCase, self).setUp()
+        super().setUp()
 
     def _get_new_messages(self, mailbox, condition=None):
         start_time = time.time()
@@ -70,8 +68,7 @@ class EmailMessageTestCase(TestCase):
                 # check if generator contains at least one element
                 message = next(messages)
                 yield message
-                for message in messages:
-                    yield message
+                yield from messages
                 return
 
             except StopIteration:
@@ -92,10 +89,7 @@ class EmailMessageTestCase(TestCase):
 
     def _get_email_object(self, name):
         copy = self._get_email_as_text(name)
-        if six.PY3:
-            return email.message_from_bytes(copy)
-        else:
-            return email.message_from_string(copy)
+        return email.message_from_bytes(copy)
 
     def _headers_identical(self, left, right, header=None):
         """ Check if headers are (close enough to) identical.
@@ -131,7 +125,7 @@ class EmailMessageTestCase(TestCase):
                 raise AssertionError("Extra header '%s'" % key)
             if not self._headers_identical(right[key], value, header=key):
                 raise AssertionError(
-                    "Header '%s' unequal:\n%s\n%s" % (
+                    "Header '{}' unequal:\n{}\n{}".format(
                         key,
                         repr(value),
                         repr(right[key]),
@@ -144,7 +138,7 @@ class EmailMessageTestCase(TestCase):
                 raise AssertionError("Extra header '%s'" % key)
             if not self._headers_identical(left[key], value, header=key):
                 raise AssertionError(
-                    "Header '%s' unequal:\n%s\n%s" % (
+                    "Header '{}' unequal:\n{}\n{}".format(
                         key,
                         repr(value),
                         repr(right[key]),
@@ -175,7 +169,7 @@ class EmailMessageTestCase(TestCase):
 
     def _raise_mismatched(self, left, right):
         raise AssertionError(
-            "Message payloads do not match:\n%s\n%s" % (
+            "Message payloads do not match:\n{}\n{}".format(
                 left.as_string(),
                 right.as_string()
             )
@@ -183,7 +177,7 @@ class EmailMessageTestCase(TestCase):
 
     def assertEqual(self, left, right):  # noqa: N802
         if not isinstance(left, email.message.Message):
-            return super(EmailMessageTestCase, self).assertEqual(left, right)
+            return super().assertEqual(left, right)
         return self.compare_email_objects(left, right)
 
     def tearDown(self):
@@ -194,4 +188,4 @@ class EmailMessageTestCase(TestCase):
         models.TEXT_STORED_MIMETYPES = self._TEXT_STORED_MIMETYPES
 
         self.mailbox.delete()
-        super(EmailMessageTestCase, self).tearDown()
+        super().tearDown()
diff --git a/django_mailbox/tests/test_integration_imap.py b/django_mailbox/tests/test_integration_imap.py
index 1110f69..6f875b7 100644
--- a/django_mailbox/tests/test_integration_imap.py
+++ b/django_mailbox/tests/test_integration_imap.py
@@ -1,7 +1,6 @@
 import os
 import uuid
-
-from six.moves.urllib import parse
+from urllib import parse
 
 from django.core.mail import EmailMultiAlternatives
 
@@ -14,7 +13,7 @@ __all__ = ['TestImap']
 
 class TestImap(EmailMessageTestCase):
     def setUp(self):
-        super(TestImap, self).setUp()
+        super().setUp()
 
         self.test_imap_server = (
             os.environ.get('EMAIL_IMAP_SERVER')
diff --git a/django_mailbox/tests/test_message_flattening.py b/django_mailbox/tests/test_message_flattening.py
index fd9a9b4..669433e 100644
--- a/django_mailbox/tests/test_message_flattening.py
+++ b/django_mailbox/tests/test_message_flattening.py
@@ -1,6 +1,6 @@
 import copy
 
-import mock
+from unittest import mock
 
 from django_mailbox import models, utils
 from django_mailbox.models import Message
diff --git a/django_mailbox/tests/test_process_email.py b/django_mailbox/tests/test_process_email.py
index 831eeaf..a6dbd04 100644
--- a/django_mailbox/tests/test_process_email.py
+++ b/django_mailbox/tests/test_process_email.py
@@ -3,8 +3,7 @@ import os.path
 import sys
 
 import copy
-import mock
-import six
+from unittest import mock
 
 from django_mailbox.models import Mailbox, Message
 from django_mailbox.utils import convert_header_to_unicode
@@ -54,18 +53,18 @@ class TestProcessEmail(EmailMessageTestCase):
 
         attachments = msg.attachments.order_by('pk').all()
         self.assertEqual(
-            u'\u041f\u0430\u043a\u0435\u0442 \u043f\u0440\u0435\u0434\u043b'
-            u'\u043e\u0436\u0435\u043d\u0438\u0439 HSE Career Fair 8 \u0430'
-            u'\u043f\u0440\u0435\u043b\u044f 2016.pdf',
+            '\u041f\u0430\u043a\u0435\u0442 \u043f\u0440\u0435\u0434\u043b'
+            '\u043e\u0436\u0435\u043d\u0438\u0439 HSE Career Fair 8 \u0430'
+            '\u043f\u0440\u0435\u043b\u044f 2016.pdf',
             attachments[0].get_filename()
         )
         self.assertEqual(
-            u'\u0412\u0435\u0434\u043e\u043c\u043e\u0441\u0442\u0438.pdf',
+            '\u0412\u0435\u0434\u043e\u043c\u043e\u0441\u0442\u0438.pdf',
             attachments[1].get_filename()
         )
         self.assertEqual(
-            u'\u041f\u0430\u043a\u0435\u0442 \u043f\u0440\u0435\u0434\u043b'
-            u'\u043e\u0436\u0435\u043d\u0438\u0439 2016.pptx',
+            '\u041f\u0430\u043a\u0435\u0442 \u043f\u0440\u0435\u0434\u043b'
+            '\u043e\u0436\u0435\u043d\u0438\u0439 2016.pptx',
             attachments[2].get_filename()
         )
 
@@ -89,33 +88,6 @@ class TestProcessEmail(EmailMessageTestCase):
             'heart.png',
         )
 
-    def test_message_with_not_decoded_attachment_header(self):
-        if sys.version_info > (3, 0):
-            self.skipTest(
-                "This test is only relevant on Python 2.x."
-            )
-
-        email_object = self._get_email_object(
-            'message_with_not_decoded_attachment_header.eml',
-        )
-
-        mailbox = Mailbox.objects.create()
-        msg = mailbox.process_incoming_message(email_object)
-
-        expected_count = 1
-        actual_count = msg.attachments.count()
-
-        self.assertEqual(
-            expected_count,
-            actual_count,
-        )
-
-        attachment = msg.attachments.all()[0]
-        self.assertEqual(
-            attachment.get_filename(),
-            u'\xc3\xb0\xcc\x9eo\xce\xb2\xcc\x9ele.png',
-        )
-
     def test_message_with_utf8_attachment_header(self):
         """ Ensure that we properly handle UTF-8 encoded attachment
 
@@ -138,13 +110,13 @@ class TestProcessEmail(EmailMessageTestCase):
         attachment = msg.attachments.all()[0]
         self.assertEqual(
             attachment.get_filename(),
-            u'pi\u0142kochwyty.jpg'
+            'pi\u0142kochwyty.jpg'
         )
 
         attachment = msg.attachments.all()[1]
         self.assertEqual(
             attachment.get_filename(),
-            u'odpowied\u017a Burmistrza.jpg'
+            'odpowied\u017a Burmistrza.jpg'
         )
 
     def test_message_get_text_body(self):
@@ -187,7 +159,7 @@ class TestProcessEmail(EmailMessageTestCase):
                 'messages/generic_message.eml'
             )
         ) as f:
-            unicode_body = six.u(f.read())
+            unicode_body = f.read()
 
         message = Message()
         message.body = unicode_body
@@ -281,10 +253,8 @@ class TestProcessEmail(EmailMessageTestCase):
 
         msg = self.mailbox.process_incoming_message(email_object)
 
-        expected_text = six.u(
-            'This message contains funny UTF16 characters like this one: '
-            '"\xc2\xa0" and this one "\xe2\x9c\xbf".'
-        )
+        expected_text = 'This message contains funny UTF16 characters ' + \
+            'like this one: "\xc2\xa0" and this one "\xe2\x9c\xbf".'
         actual_text = msg.text
 
         self.assertEqual(
@@ -320,14 +290,12 @@ class TestProcessEmail(EmailMessageTestCase):
         msg = self.mailbox.process_incoming_message(email_object)
 
         actual_text = msg.text
-        expected_body = six.u(
-            '\u042d\u0442\u043e '
-            '\u0441\u043e\u043e\u0431\u0449\u0435\u043d\u0438\u0435 '
-            '\u0438\u043c\u0435\u0435\u0442 '
-            '\u043d\u0435\u043f\u0440\u0430\u0432\u0438\u043b\u044c\u043d'
-            '\u0443\u044e '
+        expected_body = '\u042d\u0442\u043e ' + \
+            '\u0441\u043e\u043e\u0431\u0449\u0435\u043d\u0438\u0435 ' + \
+            '\u0438\u043c\u0435\u0435\u0442 ' + \
+            '\u043d\u0435\u043f\u0440\u0430\u0432\u0438\u043b\u044c\u043d' + \
+            '\u0443\u044e ' + \
             '\u043a\u043e\u0434\u0438\u0440\u043e\u0432\u043a\u0430.'
-        )
 
         self.assertEqual(
             actual_text,
@@ -341,23 +309,15 @@ class TestProcessEmail(EmailMessageTestCase):
 
         msg = self.mailbox.process_incoming_message(email_object)
 
-        expected_subject = six.u(
-            '\u00D3\u00E7\u00ED\u00E0\u00E9 \u00EA\u00E0\u00EA '
-            '\u00E7\u00E0\u00F0\u00E0\u00E1\u00E0\u00F2\u00FB\u00E2'
-            '\u00E0\u00F2\u00FC \u00EE\u00F2 1000$ \u00E2 '
+        expected_subject = '\u00D3\u00E7\u00ED\u00E0\u00E9 \u00EA\u00E0\u00EA ' + \
+            '\u00E7\u00E0\u00F0\u00E0\u00E1\u00E0\u00F2\u00FB\u00E2' + \
+            '\u00E0\u00F2\u00FC \u00EE\u00F2 1000$ \u00E2 ' + \
             '\u00ED\u00E5\u00E4\u00E5\u00EB\u00FE!'
-        )
         actual_subject = msg.subject
         self.assertEqual(actual_subject, expected_subject)
 
-        if sys.version_info >= (3, 3):
-            # There were various bugfixes in Py3k's email module,
-            # this is apparently one of them.
-            expected_from = six.u('test test <mr.test32@mail.ru>')
-        else:
-            expected_from = six.u('test test<mr.test32@mail.ru>')
+        expected_from = 'test test <mr.test32@mail.ru>'
         actual_from = msg.from_header
-
         self.assertEqual(expected_from, actual_from)
 
     def test_message_reply(self):
@@ -426,15 +386,15 @@ class TestProcessEmail(EmailMessageTestCase):
 
             msg = self.mailbox.process_incoming_message(message)
 
-        actual_email_object = msg.get_email_object()
-
         self.assertNotEquals(msg.eml, None)
 
         self.assertTrue(msg.eml.name.endswith('.eml'))
 
         with open(msg.eml.name, 'rb') as f:
-            self.assertEqual(f.read(),
-                             self._get_email_as_text('generic_message.eml'))
+            self.assertEqual(
+                f.read(),
+                self._get_email_as_text('generic_message.eml')
+            )
 
     def test_message_saving_ignored(self):
         message = self._get_email_object('generic_message.eml')
diff --git a/django_mailbox/tests/test_processincomingmessage.py b/django_mailbox/tests/test_processincomingmessage.py
index 5ec2432..8ba2fb2 100644
--- a/django_mailbox/tests/test_processincomingmessage.py
+++ b/django_mailbox/tests/test_processincomingmessage.py
@@ -1,5 +1,5 @@
 from distutils.version import LooseVersion
-import mock
+from unittest import mock
 
 from django.core.management import call_command, CommandError
 from django.test import TestCase
diff --git a/django_mailbox/tests/test_transports.py b/django_mailbox/tests/test_transports.py
index 1d3c68f..403a306 100644
--- a/django_mailbox/tests/test_transports.py
+++ b/django_mailbox/tests/test_transports.py
@@ -1,5 +1,4 @@
-import mock
-import six
+from unittest import mock
 
 from django.test.utils import override_settings
 
@@ -9,24 +8,22 @@ from django_mailbox.transports import ImapTransport, Pop3Transport
 FAKE_UID_SEARCH_ANSWER = (
     'OK',
     [
-        six.b(
-            '18 19 20 21 22 23 24 25 26 27 28 29 '
-            '30 31 32 33 34 35 36 37 38 39 40 41 42 43 44'
-        )
+        b'18 19 20 21 22 23 24 25 26 27 28 29 ' + 
+        b'30 31 32 33 34 35 36 37 38 39 40 41 42 43 44'
     ]
 )
 FAKE_UID_FETCH_SIZES = (
     'OK',
     [
-        six.b('1 (UID 18 RFC822.SIZE 58070000000)'),
-        six.b('2 (UID 19 RFC822.SIZE 2593)')
+        b'1 (UID 18 RFC822.SIZE 58070000000)',
+        b'2 (UID 19 RFC822.SIZE 2593)'
     ]
 )
 FAKE_UID_FETCH_MSG = (
     'OK',
     [
         (
-            six.b('1 (UID 18 RFC822 {5807}'),
+            b'1 (UID 18 RFC822 {5807}',
             get_email_as_text('generic_message.eml')
         ),
     ]
@@ -34,13 +31,13 @@ FAKE_UID_FETCH_MSG = (
 FAKE_UID_COPY_MSG = (
     'OK',
     [
-        six.b('[COPYUID 1 2 2] (Success)')
+        b'[COPYUID 1 2 2] (Success)'
     ]
 )
 FAKE_LIST_ARCHIVE_FOLDERS_ANSWERS = (
     'OK',
     [
-        six.b('(\\HasNoChildren \\All) "/" "[Gmail]/All Mail"')
+        b'(\\HasNoChildren \\All) "/" "[Gmail]/All Mail"'
     ]
 )
 
@@ -66,12 +63,12 @@ class IMAPTestCase(EmailMessageTestCase):
         self.imap_server = mock.Mock()
         self.imap_server.uid = imap_server_uid_method
         self.imap_server.list = imap_server_list_method
-        super(IMAPTestCase, self).setUp()
+        super().setUp()
 
 
 class TestImapTransport(IMAPTestCase):
     def setUp(self):
-        super(TestImapTransport, self).setUp()
+        super().setUp()
         self.arbitrary_hostname = 'one.two.three'
         self.arbitrary_port = 100
         self.ssl = False
@@ -92,7 +89,7 @@ class TestImapTransport(IMAPTestCase):
 
 class TestImapArchivedTransport(TestImapTransport):
     def setUp(self):
-        super(TestImapArchivedTransport, self).setUp()
+        super().setUp()
         self.archive = 'Archive'
         self.transport = ImapTransport(
             self.arbitrary_hostname,
@@ -107,7 +104,7 @@ class TestMaxSizeImapTransport(TestImapTransport):
 
     @override_settings(DJANGO_MAILBOX_MAX_MESSAGE_SIZE=5807)
     def setUp(self):
-        super(TestMaxSizeImapTransport, self).setUp()
+        super().setUp()
 
         self.transport = ImapTransport(
             self.arbitrary_hostname,
@@ -142,7 +139,7 @@ class TestPop3Transport(EmailMessageTestCase):
             self.ssl
         )
         self.transport.server = None
-        super(TestPop3Transport, self).setUp()
+        super().setUp()
 
     def test_get_email_message(self):
         with mock.patch.object(self.transport, 'server') as server:
diff --git a/django_mailbox/transports/base.py b/django_mailbox/transports/base.py
index d65ad35..a90af9f 100644
--- a/django_mailbox/transports/base.py
+++ b/django_mailbox/transports/base.py
@@ -1,19 +1,11 @@
 import email
 
-import six
-
 # Do *not* remove this, we need to use this in subclasses of EmailTransport
-if six.PY3:
-    from email.errors import MessageParseError  # noqa: F401
-else:
-    from email.Errors import MessageParseError  # noqa: F401
+from email.errors import MessageParseError  # noqa: F401
 
 
-class EmailTransport(object):
+class EmailTransport:
     def get_email_from_bytes(self, contents):
-        if six.PY3:
-            message = email.message_from_bytes(contents)
-        else:
-            message = email.message_from_string(contents)
+        message = email.message_from_bytes(contents)
 
         return message
diff --git a/django_mailbox/transports/generic.py b/django_mailbox/transports/generic.py
index 7738b8c..5832fda 100644
--- a/django_mailbox/transports/generic.py
+++ b/django_mailbox/transports/generic.py
@@ -1,5 +1,4 @@
 import sys
-import six
 
 from .base import EmailTransport
 
@@ -9,13 +8,8 @@ class GenericFileMailbox(EmailTransport):
     _path = None
 
     def __init__(self, path):
-        super(GenericFileMailbox, self).__init__()
-        if six.PY2:
-            self._path = path.encode(
-                sys.getfilesystemencoding()
-            )
-        else:
-            self._path = path
+        super().__init__()
+        self._path = path
 
     def get_instance(self):
         return self._variant(self._path)
diff --git a/django_mailbox/transports/gmail.py b/django_mailbox/transports/gmail.py
index 0922f9a..99e8189 100644
--- a/django_mailbox/transports/gmail.py
+++ b/django_mailbox/transports/gmail.py
@@ -48,7 +48,7 @@ class GmailImapTransport(ImapTransport):
                     )
                 )
 
-        auth_string = 'user=%s\1auth=Bearer %s\1\1' % (
+        auth_string = 'user={}\1auth=Bearer {}\1\1'.format(
             google_email_address,
             access_token
         )
diff --git a/django_mailbox/transports/imap.py b/django_mailbox/transports/imap.py
index 2c449c3..2599ada 100644
--- a/django_mailbox/transports/imap.py
+++ b/django_mailbox/transports/imap.py
@@ -88,7 +88,7 @@ class ImapTransport(EmailTransport):
                     safe_message_ids.append(uid)
             except ValueError as e:
                 logger.warning(
-                    "ValueError: %s working on %s" % (e, each_msg[0])
+                    "ValueError: {} working on {}".format(e, each_msg[0])
                 )
                 pass
         return safe_message_ids
diff --git a/django_mailbox/transports/pop3.py b/django_mailbox/transports/pop3.py
index 4601114..6dbe995 100644
--- a/django_mailbox/transports/pop3.py
+++ b/django_mailbox/transports/pop3.py
@@ -1,5 +1,3 @@
-import six
-
 from poplib import POP3, POP3_SSL
 
 from .base import EmailTransport, MessageParseError
@@ -24,9 +22,7 @@ class Pop3Transport(EmailTransport):
         self.server.pass_(password)
 
     def get_message_body(self, message_lines):
-        if six.PY3:
-            return six.binary_type('\r\n', 'ascii').join(message_lines)
-        return '\r\n'.join(message_lines)
+        return bytes('\r\n', 'ascii').join(message_lines)
 
     def get_message(self, condition=None):
         message_count = len(self.server.list()[1])
diff --git a/django_mailbox/utils.py b/django_mailbox/utils.py
index 48e76be..6603612 100644
--- a/django_mailbox/utils.py
+++ b/django_mailbox/utils.py
@@ -3,8 +3,6 @@ import email.header
 import logging
 import os
 
-import six
-
 from django.conf import settings
 
 
@@ -75,11 +73,8 @@ def get_settings():
 def convert_header_to_unicode(header):
     default_charset = get_settings()['default_charset']
 
-    if six.PY2 and isinstance(header, six.text_type):
-        return header
-
     def _decode(value, encoding):
-        if isinstance(value, six.text_type):
+        if isinstance(value, str):
             return value
         if not encoding or encoding == 'unknown-8bit':
             encoding = default_charset
@@ -106,7 +101,7 @@ def get_body_from_message(message, maintype, subtype):
     """
     Fetchs the body message matching main/sub content type.
     """
-    body = six.text_type('')
+    body = ''
     for part in message.walk():
         if part.get('content-disposition', '').startswith('attachment;'):
             continue
diff --git a/docs/conf.py b/docs/conf.py
index 019ae14..335f1d5 100644
--- a/docs/conf.py
+++ b/docs/conf.py
@@ -1,4 +1,3 @@
-# -*- coding: utf-8 -*-
 #
 # django-mailbox documentation build configuration file, created by
 # sphinx-quickstart on Tue Jan 22 20:29:12 2013.
@@ -40,8 +39,8 @@ source_suffix = '.rst'
 master_doc = 'index'
 
 # General information about the project.
-project = u'django-mailbox'
-copyright = u'2014, Adam Coddington'
+project = 'django-mailbox'
+copyright = '2014, Adam Coddington'
 
 # The version info for the project you're documenting, acts as replacement for
 # |version| and |release|, also used in various other places throughout the
@@ -183,8 +182,8 @@ latex_elements = {
 # Grouping the document tree into LaTeX files. List of tuples
 # (source start file, target name, title, author, documentclass [howto/manual]).
 latex_documents = [
-  ('index', 'django-mailbox.tex', u'django-mailbox Documentation',
-   u'Adam Coddington', 'manual'),
+  ('index', 'django-mailbox.tex', 'django-mailbox Documentation',
+   'Adam Coddington', 'manual'),
 ]
 
 # The name of an image file (relative to this directory) to place at the top of
@@ -213,8 +212,8 @@ latex_documents = [
 # One entry per manual page. List of tuples
 # (source start file, name, description, authors, manual section).
 man_pages = [
-    ('index', 'django-mailbox', u'django-mailbox Documentation',
-     [u'Adam Coddington'], 1)
+    ('index', 'django-mailbox', 'django-mailbox Documentation',
+     ['Adam Coddington'], 1)
 ]
 
 # If true, show URL addresses after external links.
@@ -227,8 +226,8 @@ man_pages = [
 # (source start file, target name, title, author,
 #  dir menu entry, description, category)
 texinfo_documents = [
-  ('index', 'django-mailbox', u'django-mailbox Documentation',
-   u'Adam Coddington', 'django-mailbox', 'One line description of project.',
+  ('index', 'django-mailbox', 'django-mailbox Documentation',
+   'Adam Coddington', 'django-mailbox', 'One line description of project.',
    'Miscellaneous'),
 ]
 
@@ -275,18 +274,18 @@ def process_docstring(app, what, name, obj, options, lines):
             if help_text:
                 # Add the model field to the end of the docstring as a param
                 # using the help text as the description
-                lines.append(u':param %s: %s' % (field.attname, help_text))
+                lines.append(':param {}: {}'.format(field.attname, help_text))
             else:
                 # Add the model field to the end of the docstring as a param
                 # using the verbose name as the description
-                lines.append(u':param %s: %s' % (field.attname, verbose_name))
+                lines.append(':param {}: {}'.format(field.attname, verbose_name))
 
             # Add the field's type to the docstring
             if isinstance(field, models.ForeignKey):
                 to = field.rel.to
-                lines.append(u':type %s: %s to :class:`~%s.%s`' % (field.attname, type(field).__name__, to.__module__, to.__name__))
+                lines.append(':type {}: {} to :class:`~{}.{}`'.format(field.attname, type(field).__name__, to.__module__, to.__name__))
             else:
-                lines.append(u':type %s: %s' % (field.attname, type(field).__name__))
+                lines.append(':type {}: {}'.format(field.attname, type(field).__name__))
 
     # Return the extended docstring
     return lines
diff --git a/setup.py b/setup.py
index d6e4625..2460dc0 100755
--- a/setup.py
+++ b/setup.py
@@ -27,24 +27,25 @@ setup(
     extras_require={
         'gmail-oauth2': gmail_oauth2_require
     },
+    python_requires=">=3",
     classifiers=[
         'Framework :: Django',
         'Intended Audience :: Developers',
         'License :: OSI Approved :: MIT License',
         'Operating System :: OS Independent',
         'Framework :: Django',
-        'Framework :: Django :: 1.7',
-        'Framework :: Django :: 1.8',
-        'Framework :: Django :: 1.9',
-        'Framework :: Django :: 1.10',
         'Framework :: Django :: 1.11',
+        'Framework :: Django :: 2.0',
+        'Framework :: Django :: 2.1',
+        'Framework :: Django :: 2.2',
+        'Framework :: Django :: 3.0',
         'Programming Language :: Python',
-        'Programming Language :: Python :: 2.6',
-        'Programming Language :: Python :: 2.7',
         'Programming Language :: Python :: 3',
         'Programming Language :: Python :: 3.4',
         'Programming Language :: Python :: 3.5',
         'Programming Language :: Python :: 3.6',
+        'Programming Language :: Python :: 3.7',
+        'Programming Language :: Python :: 3.8',
         'Topic :: Communications :: Email',
         'Topic :: Communications :: Email :: Post-Office',
         'Topic :: Communications :: Email :: Post-Office :: IMAP',
diff --git a/tox.ini b/tox.ini
index c7d6a2b..2b22134 100644
--- a/tox.ini
+++ b/tox.ini
@@ -2,29 +2,25 @@
 # sort by django version, next by python version
 envlist=
     flake8
-    py{27,34}-django17
-    py{34,35}-django18
-    py{27,34,35}-django19
-    py{27,34,35}-django110
-    py{27,34,35,36}-django111
-    py{34,35,36}-django20
+    py{35,36}-django111
+    py{35,36}-django20
+    py{35,36,37}-django21
+    py{35,36,37}-django22
+    py{36,37,38}-django30
 
 [testenv]
 passenv=EMAIL_IMAP_SERVER EMAIL_ACCOUNT EMAIL_PASSWORD EMAIL_SMTP_SERVER
 deps=
-    django17: django>=1.7,<1.8
-    django18: django>=1.8,<1.9
-    django19: django>=1.9,<1.10
-    django110: django>=1.10,<1.11
-    django111: django>=1.11,<2.0
-    django20: django>=2.0,<2.1
+    django111: django==1.11.*
+    django20: django==2.0.*
+    django21: django==2.0.*
+    django22: django==2.0.*
+    django30: django==3.0b1
     -r{toxinidir}/test_requirements.txt
 sitepackages=False
 commands=
-    django110: python {toxinidir}/manage.py makemigrations --check --dry-run
-    django111: python {toxinidir}/manage.py makemigrations --check --dry-run
-    django20: python {toxinidir}/manage.py makemigrations --check --dry-run
-    python manage.py test -v2 {posargs}
+    python {toxinidir}/manage.py makemigrations --check --dry-run
+    python -Wd manage.py test -v2 {posargs}
 
 [testenv:flake8]
 deps=flake8