diff --git a/modoboa/pdfcredentials/handlers.py b/modoboa/pdfcredentials/handlers.py
index ba8e1ae53..72852fcc9 100644
--- a/modoboa/pdfcredentials/handlers.py
+++ b/modoboa/pdfcredentials/handlers.py
@@ -1,5 +1,6 @@
 """PDF credentials handlers."""
 
+import logging
 import os
 
 from django.urls import reverse
@@ -10,6 +11,7 @@ from django.utils.translation import gettext as _
 from modoboa.admin import signals as admin_signals
 from modoboa.core import models as core_models
 from modoboa.core import signals as core_signals
+from modoboa.lib.exceptions import InternalError
 from modoboa.parameters import tools as param_tools
 
 from .documents import credentials
@@ -25,7 +27,14 @@ def password_updated(sender, account, password, created, **kwargs):
         "generate_at_creation")
     if (generate_at_creation and not created) or account.is_superuser:
         return
-    init_storage_dir()
+    try:
+        init_storage_dir()
+    except InternalError as e:
+        logger = logging.getLogger("modoboa.admin")
+        logger.error(
+            _("Failed to create PDF_credentials directory. "
+            "Please check the permissions or the path."),
+            exc_info=e)
     credentials(account, password)
 
 
diff --git a/modoboa/pdfcredentials/lib.py b/modoboa/pdfcredentials/lib.py
index 363703855..cfe5200c5 100644
--- a/modoboa/pdfcredentials/lib.py
+++ b/modoboa/pdfcredentials/lib.py
@@ -1,6 +1,7 @@
 """Internal library."""
 
 from io import BytesIO
+import logging
 import os
 import struct
 
@@ -18,7 +19,7 @@ from modoboa.parameters import tools as param_tools
 
 
 def init_storage_dir():
-    """Create the directory whare documents will be stored."""
+    """Create the directory where documents will be stored."""
     storage_dir = param_tools.get_global_parameter("storage_dir")
     if os.path.exists(storage_dir) and os.access(storage_dir, os.W_OK):
         return
@@ -66,17 +67,24 @@ def crypt_and_save_to_file(content, filename, length, chunksize=64*512):
     iv = os.urandom(16)
     cipher = _get_cipher(iv)
     encryptor = cipher.encryptor()
-    with open(filename, "wb") as fp:
-        fp.write(struct.pack(b"<Q", length))
-        fp.write(iv)
-        while True:
-            chunk = content.read(chunksize)
-            if not len(chunk):
-                break
-            elif len(chunk) % 16:
-                chunk += b" " * (16 - len(chunk) % 16)
-            fp.write(encryptor.update(force_bytes(chunk)))
-        fp.write(encryptor.finalize())
+    try:
+        with open(filename, "wb") as fp:
+            fp.write(struct.pack(b"<Q", length))
+            fp.write(iv)
+            while True:
+                chunk = content.read(chunksize)
+                if not len(chunk):
+                    break
+                elif len(chunk) % 16:
+                    chunk += b" " * (16 - len(chunk) % 16)
+                fp.write(encryptor.update(force_bytes(chunk)))
+            fp.write(encryptor.finalize())
+    except FileNotFoundError as e:
+        logger = logging.getLogger("modoboa.admin")
+        logger.error(
+            _("Failed to create PDF_credentials file. "
+            "Please check the permissions or the path."),
+            exc_info=e)
 
 
 def decrypt_file(filename, chunksize=24*1024):
diff --git a/pyproject.toml b/pyproject.toml
index 24352bf6d..519a26022 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -14,18 +14,19 @@ authors = [
 ]
 description = "Mail hosting made simple"
 readme = "README.rst"
-requires-python = ">=3.7"
+requires-python = ">=3.8"
 classifiers = [
     "Development Status :: 5 - Production/Stable",
     "Environment :: Web Environment",
-    "Framework :: Django :: 2.2",
+    "Framework :: Django :: 4.2",
     "Intended Audience :: System Administrators",
     "License :: OSI Approved :: ISC License (ISCL)",
     "Operating System :: OS Independent",
     "Programming Language :: Python :: 3",
-    "Programming Language :: Python :: 3.7",
     "Programming Language :: Python :: 3.8",
     "Programming Language :: Python :: 3.9",
+    "Programming Language :: Python :: 3.10",
+    "Programming Language :: Python :: 3.11",
     "Topic :: Communications :: Email",
     "Topic :: Internet :: WWW/HTTP",
 ]