Ensure lower case aliases.

fix #685

modoboa/extensions/admin/forms/account.py

@@ -264,7 +264,7 @@ class AccountFormMail(forms.Form, DynamicForm):
                 continue
             if value == "":
                 continue
-            aliases.append(value)
+            aliases.append(value.lower())
 
         for alias in self.mb.alias_set.all():
             if not alias.full_address in aliases:

modoboa/extensions/admin/forms/alias.py

@@ -74,7 +74,7 @@ class AliasForm(forms.ModelForm, DynamicForm):
             raise forms.ValidationError(
                 _("You don't have access to this domain")
             )
-        return self.cleaned_data["email"]
+        return self.cleaned_data["email"].lower()
 
     def set_recipients(self):
         """Recipients dispatching