diff --git a/modoboa/core/extensions.py b/modoboa/core/extensions.py
index 6ff68c88a..03997c150 100644
--- a/modoboa/core/extensions.py
+++ b/modoboa/core/extensions.py
@@ -51,11 +51,16 @@ class ExtensionsPool(object):
         return self.extensions[name]["instance"]
 
     def is_extension_enabled(self, name):
+        """Check if an extension is enabled or not."""
         from modoboa.core.models import Extension
 
         if not name in self.extensions:
             return False
-        return Extension.objects.get(name=name).enabled
+        try:
+            state = Extension.objects.get(name=name).enabled
+        except Extension.DoesNotExist:
+            state = False
+        return state
 
     def get_extension_infos(self, name):
         instance = self.get_extension(name)
diff --git a/modoboa/core/management/commands/manage_extensions.py b/modoboa/core/management/commands/manage_extensions.py
index 289f4c638..0806d5ba0 100644
--- a/modoboa/core/management/commands/manage_extensions.py
+++ b/modoboa/core/management/commands/manage_extensions.py
@@ -25,14 +25,20 @@ class Command(BaseCommand):
 
     def _change_extension_state(self, name, options):
         """Change the state of an extension."""
-        extension, created = Extension.objects.get_or_create(name=name)
         newstate = options["action"] == "enable"
-        if extension.enabled == newstate:
-            return
-        if newstate:
-            extension.on()
+        update_db = True
+        try:
+            extension = Extension.objects.get(name=name)
+        except Extension.DoesNotExist:
+            extension = Extension.objects.create(name=name, enabled=newstate)
+            update_db = False
         else:
-            extension.off()
+            if extension.enabled == newstate:
+                return
+        if newstate:
+            extension.on(update_db)
+        else:
+            extension.off(update_db)
 
     def handle(self, *args, **options):
         """Entry point."""
diff --git a/modoboa/core/models.py b/modoboa/core/models.py
index 095d2d080..7be04bf6f 100644
--- a/modoboa/core/models.py
+++ b/modoboa/core/models.py
@@ -418,6 +418,9 @@ class ObjectAccess(models.Model):
 
 
 class Extension(models.Model):
+
+    """A modoboa extension."""
+
     name = models.CharField(max_length=150)
     enabled = models.BooleanField(
         ugettext_lazy('enabled'),
@@ -444,9 +447,11 @@ class Extension(models.Model):
         path = os.path.realpath(sys.modules[modname].__file__)
         self.extdir = os.path.dirname(path)
 
-    def on(self):
-        self.enabled = True
-        self.save()
+    def on(self, update_db=True):
+        """Activate this extension."""
+        if update_db:
+            self.enabled = True
+            self.save()
 
         self.__get_ext_instance()
         self.instance.load()
@@ -458,14 +463,16 @@ class Extension(models.Model):
 
         events.raiseEvent("ExtEnabled", self)
 
-    def off(self):
+    def off(self, update_db=True):
+        """Disable this extension."""
         self.__get_ext_instance()
         if self.instance is None:
             return
         self.instance.destroy()
 
-        self.enabled = False
-        self.save()
+        if update_db:
+            self.enabled = False
+            self.save()
 
         if self.instance.needs_media:
             path = os.path.join(settings.MEDIA_ROOT, self.name)
diff --git a/modoboa/extensions/postfix_relay_domains/factories.py b/modoboa/extensions/postfix_relay_domains/factories.py
index c8bc6e1c5..1a0c0a5a2 100644
--- a/modoboa/extensions/postfix_relay_domains/factories.py
+++ b/modoboa/extensions/postfix_relay_domains/factories.py
@@ -14,6 +14,8 @@ class RelayDomainFactory(PermissionFactory):
     FACTORY_FOR = models.RelayDomain
 
     target_host = 'external.host.tld'
+    enabled = True
+    verify_recipients = True
     service = factory.SubFactory(ServiceFactory)
 
 
diff --git a/tests/install_from_scratch.py b/tests/install_from_scratch.py
index ef5646073..953467cc5 100644
--- a/tests/install_from_scratch.py
+++ b/tests/install_from_scratch.py
@@ -58,7 +58,7 @@ class DeployTest(unittest.TestCase):
                self.dbhost, self.projname)
         cmd = (
             "modoboa-admin.py deploy --syncdb --collectstatic --dburl %s "
-            "--domain %s --extensions all %s"
+            "--extensions all --domain %s %s"
             % (dburl, 'localhost', self.projname)
         )
         code, output = exec_cmd(cmd, cwd=self.workdir)