diff --git a/modoboa/admin/management/commands/subcommands/_export.py b/modoboa/admin/management/commands/subcommands/_export.py
index 02fb35800..91c40d929 100644
--- a/modoboa/admin/management/commands/subcommands/_export.py
+++ b/modoboa/admin/management/commands/subcommands/_export.py
@@ -1,20 +1,14 @@
 """Django management command to export admin objects."""
 
-import sys
+import csv
 
 from django.core.management.base import BaseCommand
-from django.utils import six
 from django.utils.encoding import smart_text
 
 from modoboa.core.extensions import exts_pool
 from modoboa.core.models import User
 from .... import models
 
-if six.PY2:
-    from backports import csv
-else:
-    import csv
-
 
 class ExportCommand(BaseCommand):
     """Command class."""
diff --git a/modoboa/admin/management/commands/subcommands/_import.py b/modoboa/admin/management/commands/subcommands/_import.py
index eafec60d0..d4b7054db 100644
--- a/modoboa/admin/management/commands/subcommands/_import.py
+++ b/modoboa/admin/management/commands/subcommands/_import.py
@@ -1,5 +1,6 @@
 """Django management command to import admin objects."""
 
+import csv
 import io
 import os
 
@@ -8,7 +9,6 @@ from chardet.universaldetector import UniversalDetector
 
 from django.core.management.base import BaseCommand, CommandError
 from django.db import transaction
-from django.utils import six
 from django.utils.translation import ugettext as _
 
 from modoboa.core import models as core_models
@@ -16,11 +16,6 @@ from modoboa.core.extensions import exts_pool
 from modoboa.lib.exceptions import Conflict
 from .... import signals
 
-if six.PY2:
-    from backports import csv
-else:
-    import csv
-
 
 class ImportCommand(BaseCommand):
     """Command class."""
@@ -31,7 +26,7 @@ class ImportCommand(BaseCommand):
     def add_arguments(self, parser):
         """Add extra arguments to command."""
         parser.add_argument(
-            "--sepchar", type=six.text_type, default=";",
+            "--sepchar", type=str, default=";",
             help="Separator used in file.")
         parser.add_argument(
             "--continue-if-exists", action="store_true",
@@ -41,7 +36,7 @@ class ImportCommand(BaseCommand):
             "--crypt-password", action="store_true",
             default=False, help="Encrypt provided passwords.")
         parser.add_argument(
-            "files", type=six.text_type, nargs="+", help="CSV files to import.")
+            "files", type=str, nargs="+", help="CSV files to import.")
 
     def _import(self, filename, options, encoding="utf-8"):
         """Import domains or identities."""
@@ -117,10 +112,7 @@ class ImportCommand(BaseCommand):
                             encoding=detector.result["encoding"]
                         )
                 except UnicodeDecodeError as exc:
-                    six.raise_from(
-                        CommandError(
-                            _("Unable to decode CSV file using %(encoding)s "
-                              "encoding") % detector.result
-                        ),
-                        exc
-                    )
+                    raise CommandError(
+                        _("Unable to decode CSV file using %(encoding)s "
+                          "encoding") % detector.result
+                    ) from exc
diff --git a/modoboa/admin/tests/test_export.py b/modoboa/admin/tests/test_export.py
index fa2c70303..830dd6eab 100644
--- a/modoboa/admin/tests/test_export.py
+++ b/modoboa/admin/tests/test_export.py
@@ -1,8 +1,7 @@
 """Export related test cases."""
 
 import sys
-
-from six.moves import StringIO
+from io import StringIO
 
 from django.core.management import call_command
 from django.urls import reverse
diff --git a/modoboa/admin/views/export.py b/modoboa/admin/views/export.py
index 62f91880e..5d1764a87 100644
--- a/modoboa/admin/views/export.py
+++ b/modoboa/admin/views/export.py
@@ -1,5 +1,8 @@
 """Export related views."""
 
+import csv
+from io import StringIO
+
 from rfc6266 import build_header
 
 from django.contrib.auth.decorators import (
@@ -8,17 +11,11 @@ from django.contrib.auth.decorators import (
 from django.http import HttpResponse
 from django.shortcuts import render
 from django.urls import reverse
-from django.utils import six
 from django.utils.translation import ugettext as _
 
 from ..forms import ExportDomainsForm, ExportIdentitiesForm
 from ..lib import get_domains, get_identities
 
-if six.PY2:
-    from backports import csv
-else:
-    import csv
-
 
 def _export(content, filename):
     """Export a csv file's content
@@ -50,7 +47,7 @@ def export_identities(request):
     if request.method == "POST":
         form = ExportIdentitiesForm(request.POST)
         form.is_valid()
-        fp = six.StringIO()
+        fp = StringIO()
         csvwriter = csv.writer(fp, delimiter=form.cleaned_data["sepchar"])
         identities = get_identities(
             request.user, **request.session["identities_filters"])
@@ -78,7 +75,7 @@ def export_domains(request):
     if request.method == "POST":
         form = ExportDomainsForm(request.POST)
         form.is_valid()
-        fp = six.StringIO()
+        fp = StringIO()
         csvwriter = csv.writer(fp, delimiter=form.cleaned_data["sepchar"])
         for dom in get_domains(request.user,
                                **request.session["domains_filters"]):
diff --git a/modoboa/admin/views/import_.py b/modoboa/admin/views/import_.py
index 1a2bd2711..b40e4ce28 100644
--- a/modoboa/admin/views/import_.py
+++ b/modoboa/admin/views/import_.py
@@ -1,5 +1,6 @@
 """Import related views."""
 
+import csv
 import io
 
 from reversion import revisions as reversion
@@ -10,7 +11,6 @@ from django.contrib.auth.decorators import (
 from django.db import transaction
 from django.shortcuts import render
 from django.urls import reverse
-from django.utils import six
 from django.utils.encoding import smart_text
 from django.utils.translation import ugettext as _
 
@@ -18,11 +18,6 @@ from modoboa.lib.exceptions import Conflict, ModoboaException
 from .. import signals
 from ..forms import ImportDataForm, ImportIdentitiesForm
 
-if six.PY2:
-    from backports import csv
-else:
-    import csv
-
 
 @reversion.create_revision()
 def importdata(request, formclass=ImportDataForm):
diff --git a/modoboa/core/commands/deploy.py b/modoboa/core/commands/deploy.py
index 2ff0cbfef..d750616a6 100644
--- a/modoboa/core/commands/deploy.py
+++ b/modoboa/core/commands/deploy.py
@@ -14,7 +14,6 @@ import django
 from django.core import management
 from django.template import Context, Template
 from django.utils.encoding import smart_str
-from django.utils.six.moves import input
 
 from modoboa.core.commands import Command
 from modoboa.lib.api_client import ModoAPIClient
diff --git a/modoboa/core/management/commands/clean_inactive_accounts.py b/modoboa/core/management/commands/clean_inactive_accounts.py
index dd151e882..eb5e58778 100644
--- a/modoboa/core/management/commands/clean_inactive_accounts.py
+++ b/modoboa/core/management/commands/clean_inactive_accounts.py
@@ -1,7 +1,6 @@
 """Inactive accounts cleanup tool."""
 
 from dateutil.relativedelta import relativedelta
-from six.moves import input
 
 from django.core.management.base import BaseCommand
 from django.utils import timezone
diff --git a/modoboa/core/password_hashers/base.py b/modoboa/core/password_hashers/base.py
index d91bd9be6..689ffb82a 100644
--- a/modoboa/core/password_hashers/base.py
+++ b/modoboa/core/password_hashers/base.py
@@ -13,8 +13,6 @@ from random import Random
 from django.utils.crypto import constant_time_compare
 from django.utils.encoding import force_bytes, force_text
 
-from six import with_metaclass
-
 
 class MetaHasher(type):
     """
@@ -32,7 +30,7 @@ class MetaHasher(type):
         return cls.name if not cls._weak else "{} (weak)".format(cls.name)
 
 
-class PasswordHasher(with_metaclass(MetaHasher, object)):
+class PasswordHasher(metaclass=MetaHasher):
     """
     Base class of all hashers.
     """
diff --git a/modoboa/core/tests/test_core.py b/modoboa/core/tests/test_core.py
index 82a3e42a8..14a04e50a 100644
--- a/modoboa/core/tests/test_core.py
+++ b/modoboa/core/tests/test_core.py
@@ -1,8 +1,9 @@
 """Tests for core application."""
 
+from io import StringIO
+
 import httmock
 from dateutil.relativedelta import relativedelta
-from six import StringIO
 
 from django.core import management
 from django.test import TestCase
diff --git a/modoboa/ldapsync/tests.py b/modoboa/ldapsync/tests.py
index 2e975a09b..e5a633307 100644
--- a/modoboa/ldapsync/tests.py
+++ b/modoboa/ldapsync/tests.py
@@ -2,7 +2,6 @@
 
 from unittest import skipIf
 
-from django.utils import six
 from django.utils.encoding import force_bytes, force_str
 
 from modoboa.core import factories as core_factories
@@ -36,8 +35,7 @@ class LDAPSyncTestCase(ModoTestCase):
 
     def reset_ldap_directory(self):
         try:
-            tmp_dn = force_bytes(self.dn) if six.PY2 else self.dn
-            self.conn.delete_s(tmp_dn)
+            self.conn.delete_s(self.dn)
         except ldap.NO_SUCH_OBJECT:
             pass
 
diff --git a/modoboa/lib/email_utils.py b/modoboa/lib/email_utils.py
index b9d09ae8f..8e0d3c544 100644
--- a/modoboa/lib/email_utils.py
+++ b/modoboa/lib/email_utils.py
@@ -12,7 +12,6 @@ from lxml.html import defs
 from lxml.html.clean import Cleaner
 
 from django.template.loader import render_to_string
-from django.utils import six
 from django.utils.encoding import smart_str, smart_text
 from django.utils.html import conditional_escape, escape
 from django.utils.translation import ugettext as _
@@ -130,7 +129,7 @@ class Email(object):
                     continue
                 if encoding:
                     value = smart_text(value, encoding=encoding)
-                elif isinstance(value, six.binary_type):
+                elif isinstance(value, bytes):
                     # SMTPUTF8 fallback (most of the time)
                     # Address contains non ASCII chars but is not RFC2047
                     # encoded...
@@ -138,12 +137,9 @@ class Email(object):
                     try:
                         value = value.decode(encoding["encoding"], "replace")
                     except (TypeError, UnicodeDecodeError) as exc:
-                        six.raise_from(
-                            InternalError(
-                                _("unable to determine encoding of string")
-                            ),
-                            exc
-                        )
+                        raise InternalError(
+                            _("unable to determine encoding of string")
+                        ) from exc
                 decoded_values.append(value)
             return "".join(decoded_values)
         return ""
@@ -289,8 +285,8 @@ class Email(object):
 
 def split_address(address):
     """Split an e-mail address into local part and domain."""
-    assert isinstance(address, six.text_type),\
-        "address should be of type %s" % six.text_type.__name__
+    assert isinstance(address, str),\
+        "address should be of type str"
     if "@" not in address:
         local_part = address
         domain = None
@@ -301,10 +297,10 @@ def split_address(address):
 
 def split_local_part(local_part, delimiter=None):
     """Split a local part into local part and extension."""
-    assert isinstance(local_part, six.text_type),\
-        "local_part should be of type %s" % six.text_type.__name__
-    assert isinstance(delimiter, six.text_type) or delimiter is None,\
-        "delimiter should be of type %s" % six.text_type.__name__
+    assert isinstance(local_part, str),\
+        "local_part should be of type str"
+    assert isinstance(delimiter, str) or delimiter is None,\
+        "delimiter should be of type str"
     extension = None
     if local_part.lower() in ["mailer-daemon", "double-bounce"]:
         # never split these special addresses
@@ -346,8 +342,8 @@ def split_mailbox(mailbox, return_extension=False):
 
 def decode(value_bytes, encoding, append_to_error=""):
     """Try to decode the given string."""
-    assert isinstance(value_bytes, six.binary_type),\
-        "value_bytes should be of type %s" % six.binary_type.__name__
+    assert isinstance(value_bytes, bytes),\
+        "value_bytes should be of type bytes"
     if len(value_bytes) == 0:
         # short circuit for empty strings
         return ""
@@ -360,13 +356,10 @@ def decode(value_bytes, encoding, append_to_error=""):
                 encoding["encoding"], "replace"
             )
         except (TypeError, UnicodeDecodeError) as exc:
-            six.raise_from(
-                InternalError(
-                    _("unable to determine encoding of string") +
-                    append_to_error
-                ),
-                exc
-            )
+            raise InternalError(
+                _("unable to determine encoding of string") +
+                append_to_error
+            ) from exc
     return value
 
 
@@ -378,7 +371,7 @@ def prepare_addresses(addresses, usage="header"):
     :return: a string or a list depending on usage value
     """
     result = []
-    if isinstance(addresses, six.text_type):
+    if isinstance(addresses, str):
         addresses = [addresses]
     for name, address in getaddresses(addresses):
         if not address:
diff --git a/modoboa/lib/ldap_utils.py b/modoboa/lib/ldap_utils.py
index 32d3272dd..c981c25ab 100644
--- a/modoboa/lib/ldap_utils.py
+++ b/modoboa/lib/ldap_utils.py
@@ -34,7 +34,6 @@ Extracted from `this blog
 import ldap
 
 from django.conf import settings
-from django.utils import six
 from django.utils.encoding import force_bytes, force_str
 from django.utils.translation import ugettext as _
 
@@ -66,7 +65,7 @@ class LDAPAuthBackend(object):
 
     def _get_conn(self, dn, password):
         """Get a connection from the server."""
-        conn = ldap.initialize(self.server_uri, bytes_mode=six.PY2)
+        conn = ldap.initialize(self.server_uri)
         conn.set_option(ldap.OPT_X_TLS_DEMAND, True)
         conn.set_option(ldap.OPT_DEBUG_LEVEL, 255)
         conn.simple_bind_s(