At our installation by default all ingo rules are disabled.
So we are interrested in to disable the local user procmail script, if 
no user rule is aktive.
If no local procmail script is active then the global procmail script is used.
This is easier for us for debugging.

What's the rationale for that?

We added some code to check if any rules are active:

--- ingo-h3-1.2.3/lib/Storage.php       2009-07-24 10:57:03.000000000 +0200
+++ /var/www/html/horde/ingo/lib/Storage.php    2010-03-09 
11:30:49.000000000 +0100
@@ -896,6 +896,21 @@
      }

      /**
+     * Checks, if all rules are disabled.
+     *
+     * @return boolean  True on success.
+     */
+    function allRulesDisabled()
+    {
+        foreach ($this->_filters as $id => $rule) {
+            if ($rule['disable'] == false) {
+                return false;
+            }
+        }
+        return true;
+    }
+
+    /**
       * Searches for the first rule of a certain action type and returns its
       * number.
       *

If all rules are disabled then we remove the script on the backend:

--- ingo-h3-1.2.3/lib/Ingo.php  2008-12-15 03:33:08.000000000 +0100
+++ /var/www/html/horde/ingo/lib/Ingo.php       2010-03-09 
11:34:17.000000000 +0100
@@ -153,6 +153,11 @@
          global $notification;

          $driver = Ingo::getDriver();
+        $filters = 
&$GLOBALS['ingo_storage']->retrieve(INGO_STORAGE_ACTION_FILTERS);
+        if ($filters->allRulesDisabled()) {
+            $script = '';
+            $deactivate = true;
+        }
          $res = $driver->setScriptActive($script);
          if (is_a($res, 'PEAR_Error')) {
              $msg = ($deactivate)

I appreciate your comment.

Kind regards,

René Plattner