Index: pm_email_notify/pm_email_notify.admin.inc
==============================================================
--- pm_email_notify/pm_email_notify.admin.inc 
+++ pm_email_notify/pm_email_notify.admin.inc 
@@ -30,6 +30,14 @@
     '#weight' => 1,
   );
 
+  $form['pm_email']['pm_email_notify_from'] = array(
+    '#type' => 'textfield',
+    '#title' => t('From address for notifications'),
+    '#default_value' => variable_get('pm_email_notify_from',''),
+    '#weight' => 2,
+    '#description' => 'This is the email address that notifications will come from. Leave blank to use the site default.',
+  );
+
   $form['pm_email']['pm_email_notify_subject'] = array(
     '#type' => 'textfield',
     '#title' => t('Subject of notification messages'),
Index: pm_email_notify/pm_email_notify.module
==============================================================     
--- pm_email_notify/pm_email_notify.module 
+++ pm_email_notify/pm_email_notify.module 
@@ -56,7 +56,7 @@
       // send them a new pm notification email if they did
       $params['recipient'] = $recipient;
       $params['message'] = $message;
+      drupal_mail('pm_email_notify', 'notice', $recipient->mail, user_preferred_language($recipient), $params, variable_get('pm_email_notify_from',''));
-      drupal_mail('pm_email_notify', 'notice', $recipient->mail, user_preferred_language($recipient), $params);
     }
   }
 }