diff --git a/doc/upgrade.rst b/doc/upgrade.rst
index b711bc576..b14f2b8aa 100644
--- a/doc/upgrade.rst
+++ b/doc/upgrade.rst
@@ -209,7 +209,7 @@ Required changes to :file:`settings.py`
 
 - Remove ``NEW_ADMIN_URL`` variable
 
-- Remove ``new_admin_url`` context processor
+- Remove ``new_admin_url`` and ``top_notifications`` context processors
 
 - Remove ``ckeditor`` related apps from ``INSTALLED_APPS`` variable
 
diff --git a/frontend/src/api/webmail.js b/frontend/src/api/webmail.js
index 249686b9a..067b42a2b 100644
--- a/frontend/src/api/webmail.js
+++ b/frontend/src/api/webmail.js
@@ -94,8 +94,8 @@ export default {
     }
     return repository.post('/webmail/emails/flag/', body)
   },
-  sendEmail(body) {
-    return repository.post('/webmail/emails/send/', body)
+  sendEmailFromComposeSession(uid, body) {
+    return repository.post(`/webmail/compose-sessions/${uid}/send/`, body)
   },
   getComposeSession(uid) {
     return repository.get(`/webmail/compose-sessions/${uid}/`)
diff --git a/frontend/src/components/contacts/ContactList.vue b/frontend/src/components/contacts/ContactList.vue
index 9ec7f9150..544f3efa1 100644
--- a/frontend/src/components/contacts/ContactList.vue
+++ b/frontend/src/components/contacts/ContactList.vue
@@ -46,6 +46,12 @@
           <v-spacer></v-spacer>
         </v-toolbar>
       </template>
+      <template #[`item.display_name`]="{ item }">
+        <template v-if="item.display_name">
+          {{ item.display_name }}
+        </template>
+        <template v-else> {{ item.fist_name }} {{ item.last_name }} </template>
+      </template>
       <template #[`item.emails`]="{ item }">
         {{ displayEmails(item.emails) }}
       </template>
diff --git a/frontend/src/components/webmail/AttachmentsDialog.vue b/frontend/src/components/webmail/AttachmentsDialog.vue
index 01b033d0c..55457bbd0 100644
--- a/frontend/src/components/webmail/AttachmentsDialog.vue
+++ b/frontend/src/components/webmail/AttachmentsDialog.vue
@@ -90,7 +90,7 @@ const removeAttachment = async (attachment) => {
   attachments.value.splice(index, 1)
 }
 
-api.getUploadedAttachments(props.sessionUid).then((resp) => {
-  attachments.value = resp.data
+api.getComposeSession(props.sessionUid).then((resp) => {
+  attachments.value = resp.data.attachments
 })
 </script>
diff --git a/frontend/src/components/webmail/ComposeEmailForm.vue b/frontend/src/components/webmail/ComposeEmailForm.vue
index 73d74b29f..2324acca9 100644
--- a/frontend/src/components/webmail/ComposeEmailForm.vue
+++ b/frontend/src/components/webmail/ComposeEmailForm.vue
@@ -263,7 +263,7 @@ const submit = async () => {
     body.bcc = bcc
   }
   try {
-    await api.sendEmail(body)
+    await api.sendEmailFromComposeSession(route.query.uid, body)
     router.push({ name: 'MailboxView' })
     displayNotification({ msg: $gettext('Email sent') })
   } catch (error) {
diff --git a/frontend/src/layouts/admin/AdminLayout.vue b/frontend/src/layouts/admin/AdminLayout.vue
index c03c9cd8f..1e7f1f922 100644
--- a/frontend/src/layouts/admin/AdminLayout.vue
+++ b/frontend/src/layouts/admin/AdminLayout.vue
@@ -134,7 +134,7 @@ onMounted(() => {
     capabilitiesApi.getCapabilities().then((response) => {
       isRspamdVisible.value = 'rspamd' in response.data.capabilities
       if (isRspamdVisible.value) {
-        rspamd_url.value =
+        rspamdUrl.value =
           response.data.capabilities.rspamd.location || '/rspamd'
       }
     })
diff --git a/frontend/vite.config.js b/frontend/vite.config.js
index 7320bffea..2e84f77c0 100644
--- a/frontend/vite.config.js
+++ b/frontend/vite.config.js
@@ -34,7 +34,7 @@ export default defineConfig({
     }),
   ],
   base: '/',
-  define: { 'process.env': {}, __VUE_OPTIONS_API__: false },
+  define: { 'process.env': {} },
   resolve: {
     alias: {
       '@': fileURLToPath(new URL('./src', import.meta.url)),
diff --git a/modoboa/admin/api/v1/serializers.py b/modoboa/admin/api/v1/serializers.py
index a7b0932b3..9b2a22ed7 100644
--- a/modoboa/admin/api/v1/serializers.py
+++ b/modoboa/admin/api/v1/serializers.py
@@ -1,7 +1,5 @@
 """Admin serializers."""
 
-from typing import List
-
 from django.contrib.auth import password_validation
 from django.core.exceptions import ValidationError
 from django.shortcuts import get_object_or_404
@@ -277,7 +275,7 @@ class AccountSerializer(serializers.ModelSerializer):
         """Return role."""
         return account.role
 
-    def get_domains(self, account) -> List[str]:
+    def get_domains(self, account) -> list[str]:
         """Return domains administered by this account."""
         if account.role not in ["DomainAdmins", "Resellers"]:
             return []
diff --git a/modoboa/admin/api/v2/serializers.py b/modoboa/admin/api/v2/serializers.py
index b11fbda5d..f33c19e5f 100644
--- a/modoboa/admin/api/v2/serializers.py
+++ b/modoboa/admin/api/v2/serializers.py
@@ -2,7 +2,6 @@
 
 import ipaddress
 import os
-from typing import List
 
 from django.conf import settings
 from django.core.exceptions import ValidationError
@@ -388,7 +387,7 @@ class AccountMeSerializer(v1_serializers.AccountSerializer):
     class Meta(v1_serializers.AccountSerializer.Meta):
         fields = v1_serializers.AccountSerializer.Meta.fields + ("permissions",)
 
-    def get_permissions(self, user) -> List[str]:
+    def get_permissions(self, user) -> list[str]:
         """Return available permissions for given user."""
         permissions = (
             user.user_permissions.all() | Permission.objects.filter(group__user=user)
@@ -412,7 +411,7 @@ class AccountSerializer(v1_serializers.AccountSerializer):
             return
         self.fields["resources"] = serializers.SerializerMethodField()
 
-    def get_resources(self, account) -> List[AccountResourceSerializer]:
+    def get_resources(self, account) -> list[AccountResourceSerializer]:
         if account.role == "SimpleUsers":
             return []
         resources = []
diff --git a/modoboa/admin/models/base.py b/modoboa/admin/models/base.py
index 06b71029b..cd4d4ef5a 100644
--- a/modoboa/admin/models/base.py
+++ b/modoboa/admin/models/base.py
@@ -48,7 +48,7 @@ class AdminObject(models.Model):
     def from_db(cls, db, field_names, values):
         """Store loaded values."""
         instance = super().from_db(db, field_names, values)
-        instance._loaded_values = dict(zip(field_names, values))
+        instance._loaded_values = dict(zip(field_names, values, strict=False))
         return instance
 
     @property
diff --git a/modoboa/autoreply/models.py b/modoboa/autoreply/models.py
index 8a77cd753..10070bc7f 100644
--- a/modoboa/autoreply/models.py
+++ b/modoboa/autoreply/models.py
@@ -56,7 +56,7 @@ class ARmessage(models.Model):
             )
         content = self.content % context
         name = "autoreply"
-        action = [("vacation", ":subject", self.subject, ":days", days, content)]
+        action = [("vacation", ":subject", self.subject, ":days", str(days), content)]
         if not fset.getfilter(name):
             fset.addfilter(name, condition, action)
         else:
diff --git a/modoboa/contacts/importer/__init__.py b/modoboa/contacts/importer/__init__.py
index 76b391812..6064ed4b7 100644
--- a/modoboa/contacts/importer/__init__.py
+++ b/modoboa/contacts/importer/__init__.py
@@ -1,5 +1,4 @@
 import csv
-from typing import Optional
 
 from modoboa.contacts.importer.backends.outlook import OutlookBackend
 
@@ -29,7 +28,7 @@ def import_csv_file(
     backend_name: str,
     csv_filename: str,
     delimiter: str,
-    carddav_password: Optional[str] = None,
+    carddav_password: str | None = None,
 ):
     with open(csv_filename) as fp:
         backend, rows = get_import_backend(fp, delimiter, backend_name)
diff --git a/modoboa/core/extensions.py b/modoboa/core/extensions.py
index 55551fc49..34f0baa7c 100644
--- a/modoboa/core/extensions.py
+++ b/modoboa/core/extensions.py
@@ -1,7 +1,5 @@
 """Extension management."""
 
-from typing import Dict, Optional
-
 from django.conf import settings
 from django.urls import include
 from django.urls import re_path
@@ -22,8 +20,8 @@ class ModoExtension:
     description: str = ""
     needs_media: bool = False
     always_active: bool = False
-    url: Optional[str] = None
-    topredirection_url: Optional[str] = None
+    url: str | None = None
+    topredirection_url: str | None = None
 
     def get_available_apps(self) -> list:
         return []
@@ -59,7 +57,7 @@ class ExtensionsPool:
     """The extensions manager"""
 
     def __init__(self) -> None:
-        self.extensions: Dict[str, Dict] = {}
+        self.extensions: dict[str, dict] = {}
 
     def register_extension(self, ext: ModoExtension, show: bool = True) -> None:
         """Register an extension.
@@ -69,7 +67,7 @@ class ExtensionsPool:
         """
         self.extensions[ext.name] = {"cls": ext, "show": show}
 
-    def get_extension(self, name: str) -> Optional[ModoExtension]:
+    def get_extension(self, name: str) -> ModoExtension | None:
         """Retrieve the current instance of an extension."""
         if name not in self.extensions:
             return None
diff --git a/modoboa/core/models.py b/modoboa/core/models.py
index 351fbb904..129e0f0d5 100644
--- a/modoboa/core/models.py
+++ b/modoboa/core/models.py
@@ -2,7 +2,6 @@
 
 import re
 from email.header import Header
-from typing import Optional
 
 from django.core.serializers.json import DjangoJSONEncoder
 from django.conf import settings
@@ -132,7 +131,7 @@ class User(AbstractUser):
         raw_value = smart_bytes(raw_value)
         return get_password_hasher(scheme.upper())().encrypt(raw_value)
 
-    def set_password(self, raw_value: str, curvalue: Optional[str] = None) -> None:
+    def set_password(self, raw_value: str, curvalue: str | None = None) -> None:
         """Password update.
 
         Update the current mailbox's password with the given clear
diff --git a/modoboa/imap_migration/__init__.py b/modoboa/imap_migration/__init__.py
index 6b3d80114..e944787c5 100644
--- a/modoboa/imap_migration/__init__.py
+++ b/modoboa/imap_migration/__init__.py
@@ -1,12 +1,3 @@
 """A plugin to migrate mailboxes using IMAP."""
 
-from pkg_resources import get_distribution, DistributionNotFound
-
-
-try:
-    __version__ = get_distribution(__name__).version
-except DistributionNotFound:
-    # package is not installed
-    pass
-
 default_app_config = "modoboa.imap_migration.apps.IMAPMigrationConfig"
diff --git a/modoboa/lib/exceptions.py b/modoboa/lib/exceptions.py
index 1ddfb8ecd..2de2ae340 100644
--- a/modoboa/lib/exceptions.py
+++ b/modoboa/lib/exceptions.py
@@ -4,8 +4,6 @@
 
 """
 
-from typing import Optional
-
 from django.utils.translation import gettext as _
 
 
@@ -14,7 +12,7 @@ class ModoboaException(Exception):
     Base class for Modoboa custom exceptions.
     """
 
-    http_code: Optional[int] = None
+    http_code: int | None = None
 
     def __init__(self, *args, **kwargs):
         if "http_code" in kwargs:
diff --git a/modoboa/limits/tests/test_user_limits.py b/modoboa/limits/tests/test_user_limits.py
index 6d14df96c..ccd144059 100644
--- a/modoboa/limits/tests/test_user_limits.py
+++ b/modoboa/limits/tests/test_user_limits.py
@@ -1,7 +1,5 @@
 """Test cases for the limits extension."""
 
-from typing import Optional
-
 from django.urls import reverse
 
 from modoboa.admin.factories import populate_database
@@ -76,7 +74,7 @@ class ResourceTestCase(lib_tests.ModoAPITestCase):
         self.assertEqual(response.status_code, status)
         return response
 
-    def _create_alias(self, email, rcpt: Optional[list] = None, status=201):
+    def _create_alias(self, email, rcpt: list | None = None, status=201):
         if rcpt is None:
             rcpt = ["user@test.com"]
         values = {"address": email, "recipients": rcpt, "enabled": True}
diff --git a/modoboa/parameters/tools.py b/modoboa/parameters/tools.py
index 44ebed708..6ad51bef1 100644
--- a/modoboa/parameters/tools.py
+++ b/modoboa/parameters/tools.py
@@ -1,7 +1,6 @@
 """Parameters management."""
 
 import copy
-from typing import Optional
 
 from rest_framework.fields import empty
 
@@ -102,7 +101,7 @@ class Registry:
             raise NotDefined(app)
         return self._registry2[level][app]["serializer_class"]
 
-    def get_structure(self, level: str, for_app: Optional[str] = None) -> list:
+    def get_structure(self, level: str, for_app: str | None = None) -> list:
         """Return fields structure."""
         result = []
         for app, fields in list(self._registry2[level].items()):
@@ -141,7 +140,7 @@ class Registry:
                 result.append(item)
         return result
 
-    def exists(self, level: str, app: str, parameter: Optional[str] = None) -> bool:
+    def exists(self, level: str, app: str, parameter: str | None = None) -> bool:
         """Check if parameter exists."""
         parameters = self._registry2[level]
         result = app in parameters
@@ -193,7 +192,7 @@ class Manager:
             return self._parameters[app].get(parameter, default)
         return default
 
-    def get_values(self, app: Optional[str] = None):
+    def get_values(self, app: str | None = None):
         """Return all values for the given level/app."""
         if app is None:
             app = guess_extension_name()
@@ -225,7 +224,7 @@ class Manager:
             )
         self._parameters[app][parameter] = value
 
-    def set_values(self, values: dict, app: Optional[str] = None) -> None:
+    def set_values(self, values: dict, app: str | None = None) -> None:
         """Set/update values for the given app."""
         if app is None:
             app = guess_extension_name()
diff --git a/modoboa/rspamd/admin.py b/modoboa/rspamd/admin.py
index 13be29d96..846f6b406 100644
--- a/modoboa/rspamd/admin.py
+++ b/modoboa/rspamd/admin.py
@@ -1,6 +1 @@
-# -*- coding: utf-8 -*-
-from __future__ import unicode_literals
-
-from django.contrib import admin
-
 # Register your models here.
diff --git a/modoboa/sievefilters/__init__.py b/modoboa/sievefilters/__init__.py
index a48e9b877..82d26c218 100644
--- a/modoboa/sievefilters/__init__.py
+++ b/modoboa/sievefilters/__init__.py
@@ -1,12 +1,3 @@
 """The sieve filters editor of Modoboa."""
 
-from pkg_resources import get_distribution, DistributionNotFound
-
-
-try:
-    __version__ = get_distribution(__name__).version
-except DistributionNotFound:
-    # package is not installed
-    pass
-
-default_app_config = "modoboa_sievefilters.apps.SieveFiltersConfig"
+default_app_config = "modoboa.sievefilters.apps.SieveFiltersConfig"
diff --git a/modoboa/sievefilters/api/v2/serializers.py b/modoboa/sievefilters/api/v2/serializers.py
index b101b2749..2575fef81 100644
--- a/modoboa/sievefilters/api/v2/serializers.py
+++ b/modoboa/sievefilters/api/v2/serializers.py
@@ -1,7 +1,5 @@
 """Sievefilters serializers."""
 
-from typing import List, Tuple
-
 from sievelib import commands
 from sievelib.factory import Filter
 
@@ -61,7 +59,7 @@ class FilterSerializer(serializers.Serializer):
     actions = ActionSerializer(many=True)
 
     @staticmethod
-    def from_filters(filters: List[Filter]) -> "FilterSerializer":
+    def from_filters(filters: list[Filter]) -> "FilterSerializer":
         result = []
         for fobj in filters:
             if fobj["name"] == "autoreply":
@@ -117,9 +115,9 @@ class FilterSerializer(serializers.Serializer):
             result.append(item)
         return FilterSerializer(result, many=True)
 
-    def to_filter(self) -> Tuple[str, List, List]:
+    def to_filter(self) -> tuple[str, list, list]:
         """Convert serializer data to filter representation."""
-        conditions: List[Tuple] = []
+        conditions: list[tuple] = []
         actions = []
         match_type = self.validated_data["match_type"]
         if match_type == "all":
diff --git a/modoboa/sievefilters/api/v2/vloaders.py b/modoboa/sievefilters/api/v2/vloaders.py
index d8b9787b3..dffdb2aa4 100644
--- a/modoboa/sievefilters/api/v2/vloaders.py
+++ b/modoboa/sievefilters/api/v2/vloaders.py
@@ -1,6 +1,6 @@
 """Value loading functions."""
 
-from typing import List, Optional, TypedDict
+from typing import TypedDict
 
 from modoboa.webmail.lib import imaputils
 
@@ -13,9 +13,9 @@ class UserMailbox(TypedDict):
 
 
 def __build_folders_list(
-    folders: list, user, imapc: imaputils.IMAPconnector, parentmb: Optional[str] = None
-) -> List[UserMailbox]:
-    ret: List[UserMailbox] = []
+    folders: list, user, imapc: imaputils.IMAPconnector, parentmb: str | None = None
+) -> list[UserMailbox]:
+    ret: list[UserMailbox] = []
     for fd in folders:
         value = fd["path"] if "path" in fd else fd["name"]
         if parentmb:
@@ -33,7 +33,7 @@ def __build_folders_list(
     return ret
 
 
-def user_mailboxes(request) -> List[UserMailbox]:
+def user_mailboxes(request) -> list[UserMailbox]:
     """Retrieve list of available mailboxes for given user."""
     with imaputils.get_imapconnector(request, with_namespaces=False) as mbc:
         ret = mbc.getmboxes(request.user)
diff --git a/modoboa/sievefilters/lib.py b/modoboa/sievefilters/lib.py
index 3ee538cf8..fa12b776c 100644
--- a/modoboa/sievefilters/lib.py
+++ b/modoboa/sievefilters/lib.py
@@ -1,7 +1,5 @@
 """Internal tools."""
 
-from typing import Optional, Tuple, Union
-
 from sievelib.factory import FiltersSet
 from sievelib import managesieve
 from sievelib.parser import Parser
@@ -27,7 +25,7 @@ class SieveClient:
 
     msc: managesieve.Client
 
-    def __init__(self, user: Optional[str] = None, password: Optional[str] = None):
+    def __init__(self, user: str | None = None, password: str | None = None):
         if user and password:
             try:
                 ret, msg = self.login(user, password)
@@ -36,9 +34,9 @@ class SieveClient:
             if not ret:
                 raise SieveClientError(msg)
 
-    def login(self, user: str, password: str) -> Tuple[bool, Union[str, None]]:
+    def login(self, user: str, password: str) -> tuple[bool, str | None]:
         conf = dict(param_tools.get_global_parameters("sievefilters"))
-        self.msc = managesieve.Client(conf["server"], conf["port"], debug=True)
+        self.msc = managesieve.Client(conf["server"], conf["port"], debug=False)
         try:
             ret = self.msc.connect(
                 user, password, starttls=conf["starttls"], authmech="OAUTHBEARER"
@@ -59,7 +57,7 @@ class SieveClient:
     def listscripts(self):
         return self.msc.listscripts()
 
-    def getscript(self, name: str, format: str = "raw") -> Union[FiltersSet, str, None]:
+    def getscript(self, name: str, format: str = "raw") -> FiltersSet | str | None:
         content = self.msc.getscript(name)
         if content is None:
             raise SieveClientError(self.msc.errmsg.decode())
diff --git a/modoboa/webmail/lib/attachments.py b/modoboa/webmail/lib/attachments.py
index 53ca33e93..391139762 100644
--- a/modoboa/webmail/lib/attachments.py
+++ b/modoboa/webmail/lib/attachments.py
@@ -3,7 +3,6 @@ from email.mime.base import MIMEBase
 import json
 import os
 from tempfile import NamedTemporaryFile
-from typing import Optional
 import uuid
 
 import six
@@ -81,7 +80,7 @@ def save_attachment(request, session_uid: str, f) -> dict:
         fp = NamedTemporaryFile(dir=get_storage_path(""), delete=False)
     except Exception as e:
         raise InternalError(str(e)) from None
-    if isinstance(f, (six.binary_type, six.text_type)):
+    if isinstance(f, six.binary_type | six.text_type):
         fp.write(smart_bytes(f))
     else:
         for chunk in f.chunks():
@@ -100,7 +99,7 @@ def save_attachment(request, session_uid: str, f) -> dict:
     return attachment
 
 
-def remove_attachment(request, session_uid: str, name: str) -> Optional[str]:
+def remove_attachment(request, session_uid: str, name: str) -> str | None:
     manager = ComposeSessionManager(request.user.username)
     session = manager.get_content(session_uid)
     for att in session["attachments"]:
diff --git a/modoboa/webmail/lib/imaputils.py b/modoboa/webmail/lib/imaputils.py
index 8b36a64b3..706e6ebc0 100644
--- a/modoboa/webmail/lib/imaputils.py
+++ b/modoboa/webmail/lib/imaputils.py
@@ -5,7 +5,6 @@ import imaplib
 import re
 import ssl
 import time
-from typing import Optional
 
 from django.conf import settings
 from django.utils.translation import gettext as _
@@ -108,7 +107,7 @@ class BodyStructure:
         self.attachments += [params]
 
     def load_from_definition(
-        self, definition: list, multisubtype: Optional[str] = None
+        self, definition: list, multisubtype: str | None = None
     ) -> None:
         for mp in definition:
             if isinstance(mp, list):
@@ -148,11 +147,11 @@ class IMAPconnector:
     unseen_pattern = re.compile(r"[^\(]+\(UNSEEN (\d+)\)")
 
     def __init__(self, user: str, password: str, with_namespaces: bool = True) -> None:
-        self.__hdelimiter: Optional[str] = None
+        self.__hdelimiter: str | None = None
         self.__ns_prefixes: dict = {}
         self.quota_usage: int = -1
-        self.quota_limit: Optional[int] = None
-        self.quota_current: Optional[int] = None
+        self.quota_limit: int | None = None
+        self.quota_current: int | None = None
         self.criterions: list = []
         self.conf = dict(param_tools.get_global_parameters("webmail"))
         self.address = self.conf["imap_server"]
@@ -170,7 +169,7 @@ class IMAPconnector:
     def __exit__(self, *args):
         self.logout()
 
-    def _cmd(self, name: str, *args, **kwargs) -> Optional[list]:
+    def _cmd(self, name: str, *args, **kwargs) -> list | None:
         """IMAP command wrapper.
 
         To simplify errors handling, this wrapper calls the
@@ -240,7 +239,8 @@ class IMAPconnector:
         except (OSError, imaplib.IMAP4.error, ssl.SSLError) as error:
             raise ImapError(_(f"Connection to IMAP server failed: {error}")) from None
 
-        if not settings.WEBMAIL_DEV_MODE:
+        dev_mode = getattr(settings, "WEBMAIL_DEV_MODE", False)
+        if not dev_mode:
             token = oauth2.build_oauthbearer_string(user, rawtoken)
             data = self._cmd("AUTHENTICATE", b"OAUTHBEARER", token)
         else:
@@ -600,7 +600,7 @@ class IMAPconnector:
         self.select_mailbox(mbox, False)
         self._cmd("EXPUNGE")
 
-    def create_folder(self, name: str, parent: Optional[str] = None) -> bool:
+    def create_folder(self, name: str, parent: str | None = None) -> bool:
         if parent is not None:
             name = f"{parent}{self.hdelimiter}{name}"
         typ, data = self.m.create(self._encode_mbox_name(name))
@@ -675,7 +675,7 @@ class IMAPconnector:
         return attdef, data[int(uid)][f"BODY[{partnum}]"]
 
     def fetch(
-        self, start: int, stop: Optional[int] = None, mbox: Optional[str] = None
+        self, start: int, stop: int | None = None, mbox: str | None = None
     ) -> list:
         """Retrieve information about messages from the server.
 
@@ -748,7 +748,7 @@ class IMAPconnector:
         return data[int(mailid)]
 
 
-def separate_mailbox(fullname: str, sep: str = ".") -> tuple[str, Optional[str]]:
+def separate_mailbox(fullname: str, sep: str = ".") -> tuple[str, str | None]:
     """Split a mailbox name.
 
     If a separator is found in ``fullname``, this function returns the
diff --git a/modoboa/webmail/lib/sendmail.py b/modoboa/webmail/lib/sendmail.py
index a5b6b8cd9..bc178b38e 100644
--- a/modoboa/webmail/lib/sendmail.py
+++ b/modoboa/webmail/lib/sendmail.py
@@ -3,7 +3,6 @@ from email.mime.image import MIMEImage
 import os
 import pkg_resources
 import smtplib
-from typing import Optional, Tuple
 from urllib.parse import unquote, urlparse
 
 import lxml
@@ -20,7 +19,7 @@ from modoboa.webmail.lib.utils import html2plaintext
 from . import get_imapconnector
 
 
-def make_body_images_inline(body: str) -> Tuple[str, list]:
+def make_body_images_inline(body: str) -> tuple[str, list]:
     """Look for images inside the body and make them inline.
 
     Before sending a message in HTML format, it is necessary to find
@@ -117,9 +116,7 @@ def create_message(user: core_models.User, attributes: dict, attachments: list):
     return msg
 
 
-def send_mail(
-    request, attributes: dict, attachments: list
-) -> Tuple[bool, Optional[str]]:
+def send_mail(request, attributes: dict, attachments: list) -> tuple[bool, str | None]:
     """
     Send a new email.