diff --git a/modoboa/extensions/amavis/management/commands/amnotify.py b/modoboa/extensions/amavis/management/commands/amnotify.py
index 209350da3..d9962b93f 100644
--- a/modoboa/extensions/amavis/management/commands/amnotify.py
+++ b/modoboa/extensions/amavis/management/commands/amnotify.py
@@ -16,10 +16,14 @@ from modoboa.extensions.admin.models import Domain
 from modoboa.extensions.amavis.models import (
     Msgrcpt
 )
-from modoboa.extensions.amavis.sql_connector import get_connector
+from ...modo_extension import Amavis
+from ...sql_connector import get_connector
 
 
 class Command(BaseCommand, CloseConnectionMixin):
+
+    """A management command to notify admins about pending release requests."""
+
     help = 'Amavis notification tool'
 
     sender = None
@@ -40,6 +44,7 @@ class Command(BaseCommand, CloseConnectionMixin):
     def handle(self, *args, **options):
         if options["baseurl"] is None:
             raise CommandError("You must provide the --baseurl option")
+        Amavis.load()
         self.options = options
         self.notify_admins_pending_requests()
 
diff --git a/modoboa/extensions/amavis/management/commands/qcleanup.py b/modoboa/extensions/amavis/management/commands/qcleanup.py
index 47e2d6dce..34dcdc060 100644
--- a/modoboa/extensions/amavis/management/commands/qcleanup.py
+++ b/modoboa/extensions/amavis/management/commands/qcleanup.py
@@ -11,6 +11,7 @@ from modoboa.extensions.amavis.models import (
     Msgrcpt, Msgs, Maddr
 )
 from modoboa.lib import parameters
+from ...modo_extension import Amavis
 
 
 class Command(BaseCommand, CloseConnectionMixin):
@@ -34,6 +35,7 @@ class Command(BaseCommand, CloseConnectionMixin):
         print msg
 
     def handle(self, *args, **options):
+        Amavis.load()
         if options["debug"]:
             import logging
             l = logging.getLogger("django.db.backends")
diff --git a/modoboa/extensions/postfix_autoreply/management/commands/autoreply.py b/modoboa/extensions/postfix_autoreply/management/commands/autoreply.py
index 09482185c..44d2ed172 100644
--- a/modoboa/extensions/postfix_autoreply/management/commands/autoreply.py
+++ b/modoboa/extensions/postfix_autoreply/management/commands/autoreply.py
@@ -10,7 +10,8 @@ from modoboa.core.management.commands import CloseConnectionMixin
 from modoboa.lib import parameters
 from modoboa.lib.email_utils import split_mailbox, sendmail_simple
 from modoboa.extensions.admin.models import Mailbox
-from modoboa.extensions.postfix_autoreply.models import ARmessage, ARhistoric
+from ...models import ARmessage, ARhistoric
+from ...modo_extension import PostfixAutoreply
 
 
 def send_autoreply(sender, mailbox, armessage):
@@ -52,6 +53,7 @@ class Command(BaseCommand, CloseConnectionMixin):
             raise CommandError(
                 "usage: ./manage.py autoreply <sender> <recipient ...>")
 
+        PostfixAutoreply.load()
         sender = args[0]
         for fulladdress in args[1:]:
             address, domain = split_mailbox(fulladdress)
diff --git a/modoboa/extensions/radicale/management/commands/generate_rights.py b/modoboa/extensions/radicale/management/commands/generate_rights.py
index 3dd857c97..25365c514 100644
--- a/modoboa/extensions/radicale/management/commands/generate_rights.py
+++ b/modoboa/extensions/radicale/management/commands/generate_rights.py
@@ -8,9 +8,10 @@ from modoboa.core.management.commands import CloseConnectionMixin
 from modoboa.core.models import User
 from modoboa.lib import parameters
 from modoboa.extensions.admin.models import Domain
-from modoboa.extensions.radicale.models import (
+from ...models import (
     AccessRule
 )
+from ...modo_extension import Radicale
 
 
 class Command(BaseCommand, CloseConnectionMixin):
@@ -102,6 +103,7 @@ permission = %s
 
     def handle(self, *args, **options):
         """Command entry point."""
+        Radicale.load()
         path = parameters.get_admin("RIGHTS_FILE_PATH", app="radicale")
         if not options["force"]:
             try:
diff --git a/modoboa/extensions/stats/management/commands/logparser.py b/modoboa/extensions/stats/management/commands/logparser.py
index 1f38ff6fa..089c374ab 100644
--- a/modoboa/extensions/stats/management/commands/logparser.py
+++ b/modoboa/extensions/stats/management/commands/logparser.py
@@ -33,6 +33,7 @@ from modoboa.core.management.commands import CloseConnectionMixin
 from modoboa.extensions.admin.models import Domain
 from modoboa.extensions.stats.lib import date_to_timestamp
 from modoboa.lib import parameters
+from ...modo_extension import Stats
 
 rrdstep = 60
 xpoints = 540
@@ -372,6 +373,7 @@ class Command(BaseCommand, CloseConnectionMixin):
     )
 
     def handle(self, *args, **options):
+        Stats.load()
         if options["logfile"] is None:
             options["logfile"] = parameters.get_admin("LOGFILE", app="stats")
         p = LogParser(options, parameters.get_admin("RRD_ROOTDIR", app="stats"))
diff --git a/modoboa/extensions/stats/modo_extension.py b/modoboa/extensions/stats/modo_extension.py
index 926063168..8711a60e0 100644
--- a/modoboa/extensions/stats/modo_extension.py
+++ b/modoboa/extensions/stats/modo_extension.py
@@ -7,7 +7,6 @@ This module provides support to retrieve statistics from postfix log :
 sent, received, bounced, rejected
 
 """
-import sys
 
 from django.utils.translation import ugettext_lazy