diff --git a/models/Postmaster_NotificationModel.php b/models/Postmaster_NotificationModel.php
index 1b01983..eaffe35 100644
--- a/models/Postmaster_NotificationModel.php
+++ b/models/Postmaster_NotificationModel.php
@@ -81,38 +81,51 @@ public function getNotificationSchedule($class = false)
 
     public function marshal()
     {
+        // Get the notification schedule instance
         $notificationSchedule = $this->getNotificationSchedule();
 
+        // Check to see if the notification should send by passing the last 
+        // time the notification was sent as a Carbon\Carbon object
         if($notificationSchedule->shouldSend($this->lastSent()))
         {
+            // Get the notification type instance
             $notificationType = $this->getNotificationType();
-        
+            
+            // Create a new Postmaster_TransportModel object
             $transport = new Postmaster_TransportModel(array(
                 'service' => $this->service,
                 'settings' => $notificationType->getSettings(),
                 'data' => array()
             ));
 
-            if( $notificationType->onBeforeSend($transport) !== false && 
-                $notificationSchedule->onBeforeSend($transport) !== false)
+            // Call onBeforeSend methods to the notification schedule and notification type
+            // If either instance returns false, the message will not be sent
+            if( $notificationSchedule->onBeforeSend($transport) !== false &&
+                $notificationType->onBeforeSend($transport) !== false )
             {
+                // Send the transport object
                 $response = $this->send($transport);
                     
                 // Test the service response for correct class and throw an error if it fails
                 if(!$response instanceof \Craft\Postmaster_TransportResponseModel)
                 {
-                    throw new Exception('The '.$notificationSchedule->service->name.' service did not return a \Craft\Postmaster_TransportResponseModel');
+                    throw new Exception('The '.$notificationSchedule->getService()->name.' service did not return a \Craft\Postmaster_TransportResponseModel');
                 }
 
+                // Call the onAfterSend method on the notification schedule
                 $notificationSchedule->onAfterSend($response);
 
+                // Call the onAfterSend method on the notification type
                 $notificationType->onAfterSend($response);
 
                 // Save the response to the db
                 $response->save();
 
+                // If the response is a success, create a notification sent record
                 if($response->getSuccess())
                 {
+                    // Pass $this object to the createSentNotification method to
+                    // create the actual record in the db
                     craft()->postmaster_notifications->createSentNotification($this);
                 }
             }
diff --git a/models/Postmaster_ParcelModel.php b/models/Postmaster_ParcelModel.php
index 4ea12f6..47d4dd3 100644
--- a/models/Postmaster_ParcelModel.php
+++ b/models/Postmaster_ParcelModel.php
@@ -31,31 +31,41 @@ public function lastSent()
 
     public function send(Postmaster_TransportModel $transport)
     {
-        $lastSent = craft()->postmaster_parcels->lastSent($this->id);
+        // Get the parcel schedule instance
+        $parcelSchedule = $this->getParcelSchedule();
 
-        if($this->getParcelSchedule()->shouldSend($lastSent))
+        // Check to see if the notification should send by passing the last 
+        // time the notification was sent as a Carbon\Carbon object
+        if($parcelSchedule->shouldSend($this->lastSent()))
         {
+            // Get the parcel type instance
             $parcelType = $this->getParcelType();
 
-            $parcelSchedule = $this->getParcelSchedule();
-
-            if( $parcelType->onBeforeSend($transport) !== false && 
-                $parcelSchedule->onBeforeSend($transport) !== false)
+            // Call onBeforeSend methods to the parcel schedule and parcel type
+            // If either instance returns false, the message will not be sent
+            if( $parcelSchedule->onBeforeSend($transport) !== false && 
+                $parcelType->onBeforeSend($transport) !== false )
             {
+                // Send the transport object
                 $response = parent::send($transport);
                     
-                // Test the parcel response for correct class and throw an error if it fails
+                // Test the service response for correct class and throw an error if it fails
                 if(!$response instanceof \Craft\Postmaster_TransportResponseModel)
                 {
-                    throw new Exception('The '.$transport->service->name.' service did not return a \Craft\Postmaster_TransportResponseModel');
+                    throw new Exception('The '.$parcelSchedule->getService()->name.' service did not return a \Craft\Postmaster_TransportResponseModel');
                 }
 
+                // Call on the onAfterSend method for the parcel schedule
                 $parcelSchedule->onAfterSend($response);
 
+                // Call on the onAfterSend method for the parcel type
                 $parcelType->onAfterSend($response);
 
+                // If the response is a success, create a parcel sent record
                 if($response->getSuccess())
                 {
+                    // Pass $this object to the createSentParcel method to
+                    // create the actual record in the db
                     craft()->postmaster_parcels->createSentParcel($this);
                 }
             }