diff --git a/plugins/calendar/calendar.php b/plugins/calendar/calendar.php
index e3597124..4a8cb922 100644
--- a/plugins/calendar/calendar.php
+++ b/plugins/calendar/calendar.php
@@ -61,7 +61,6 @@ class calendar extends rcube_plugin
   private $ical;
   private $itip;
   private $driver;
-  private $ics_parts = array();
 
 
   /**
@@ -2469,7 +2468,7 @@ class calendar extends rcube_plugin
   public function mail_messages_list($p)
   {
     if (in_array('attachment', (array)$p['cols']) && !empty($p['messages'])) {
-      foreach ($p['messages'] as $i => $header) {
+      foreach ($p['messages'] as $header) {
         $part = new StdClass;
         $part->mimetype = $header->ctype;
         if (libcalendaring::part_is_vcalendar($part)) {
@@ -2873,7 +2872,7 @@ class calendar extends rcube_plugin
       $part = $imap->get_message_part($uid, $mime_id);
       if ($part->ctype_parameters['charset'])
         $charset = $part->ctype_parameters['charset'];
-      $headers = $imap->get_message_headers($uid);
+//      $headers = $imap->get_message_headers($uid);
 
       if ($part) {
         $events = $this->get_ical()->import($part, $charset);
diff --git a/plugins/calendar/drivers/database/database_driver.php b/plugins/calendar/drivers/database/database_driver.php
index 891e7b89..e4bdd683 100644
--- a/plugins/calendar/drivers/database/database_driver.php
+++ b/plugins/calendar/drivers/database/database_driver.php
@@ -1186,7 +1186,7 @@ class database_driver extends calendar_driver
           " WHERE user_id=?",
           $user->ID);
 
-      while ($row = $db->fetch_assoc($calendars)) {
+      while ($row = $db->fetch_assoc($events)) {
           $event_ids[] = $row['event_id'];
       }
 
diff --git a/plugins/calendar/drivers/kolab/kolab_calendar.php b/plugins/calendar/drivers/kolab/kolab_calendar.php
index 85a3b632..60d8b4c5 100644
--- a/plugins/calendar/drivers/kolab/kolab_calendar.php
+++ b/plugins/calendar/drivers/kolab/kolab_calendar.php
@@ -148,7 +148,6 @@ class kolab_calendar extends kolab_storage_folder_api
    */
   public function get_caldav_url()
   {
-    $url = null;
     if ($template = $this->cal->rc->config->get('calendar_caldav_url', null)) {
       return strtr($template, array(
         '%h' => $_SERVER['HTTP_HOST'],
diff --git a/plugins/calendar/drivers/kolab/kolab_user_calendar.php b/plugins/calendar/drivers/kolab/kolab_user_calendar.php
index 7687e3e5..7241dd16 100644
--- a/plugins/calendar/drivers/kolab/kolab_user_calendar.php
+++ b/plugins/calendar/drivers/kolab/kolab_user_calendar.php
@@ -225,7 +225,7 @@ class kolab_user_calendar extends kolab_calendar
     }
 
     $events = array();
-    foreach ($this->events as $id => $event) {
+    foreach ($this->events as $event) {
       // list events in requested time window
       if ($event['start'] <= $end_dt && $event['end'] >= $start_dt &&
            (!$limit_changed || !$event['changed'] || $event['changed'] >= $limit_changed)) {
@@ -310,8 +310,6 @@ class kolab_user_calendar extends kolab_calendar
       $ical = $this->cal->get_ical();
       $ical->import($fbdata);
       if ($fb = $ical->freebusy) {
-        $result = array();
-
         // consider 'changed >= X' queries
         if ($limit_changed && $fb['created'] && $fb['created'] < $limit_changed) {
           return 0;
diff --git a/plugins/kolab_activesync/kolab_activesync.php b/plugins/kolab_activesync/kolab_activesync.php
index b28e7cd3..ebef64c4 100644
--- a/plugins/kolab_activesync/kolab_activesync.php
+++ b/plugins/kolab_activesync/kolab_activesync.php
@@ -86,7 +86,6 @@ class kolab_activesync extends rcube_plugin
     function folder_form($args)
     {
         $mbox_imap = $args['options']['name'];
-        $myrights  = $args['options']['rights'];
 
         // Edited folder name (empty in create-folder mode)
         if (!strlen($mbox_imap)) {
diff --git a/plugins/kolab_addressbook/kolab_addressbook.php b/plugins/kolab_addressbook/kolab_addressbook.php
index 9511e26a..a78f7ca0 100644
--- a/plugins/kolab_addressbook/kolab_addressbook.php
+++ b/plugins/kolab_addressbook/kolab_addressbook.php
@@ -102,7 +102,6 @@ class kolab_addressbook extends rcube_plugin
     public function address_sources($p)
     {
         $abook_prio = $this->addressbook_prio();
-        $undelete   = $this->rc->config->get('undo_timeout');
 
         // Disable all global address books
         // Assumes that all non-kolab_addressbook sources are global
@@ -239,7 +238,6 @@ class kolab_addressbook extends rcube_plugin
      */
     protected function addressbook_list_item($id, $source, &$jsdata, $search_mode = false)
     {
-        $folder  = $this->folders[$id];
         $current = rcube_utils::get_input_value('_source', rcube_utils::INPUT_GPC);
 
         if (!$source['virtual']) {
@@ -433,7 +431,6 @@ class kolab_addressbook extends rcube_plugin
             }
 
             // convert to UTF8 and sort
-            $names = array();
             foreach ($folders as $folder) {
                 // create instance of rcube_contacts
                 $abook_id = $folder->id;
@@ -632,7 +629,6 @@ class kolab_addressbook extends rcube_plugin
             $props['parent'] = kolab_storage::folder_id($kolab_folder->get_parent(), true);
 
             $this->rc->output->show_message('kolab_addressbook.book'.$type.'d', 'confirmation');
-            $this->rc->output->command('set_env', 'delimiter', $delimiter);
             $this->rc->output->command('book_update', $props, kolab_storage::folder_id($prop['oldname'], true));
             $this->rc->output->send('iframe');
         }
diff --git a/plugins/kolab_addressbook/lib/rcube_kolab_contacts.php b/plugins/kolab_addressbook/lib/rcube_kolab_contacts.php
index 9b2c1e02..3b4a3f6a 100644
--- a/plugins/kolab_addressbook/lib/rcube_kolab_contacts.php
+++ b/plugins/kolab_addressbook/lib/rcube_kolab_contacts.php
@@ -213,7 +213,6 @@ class rcube_kolab_contacts extends rcube_addressbook
      */
     public function get_carddav_url()
     {
-      $url = null;
       $rcmail = rcmail::get_instance();
       if ($template = $rcmail->config->get('kolab_addressbook_carddav_url', null)) {
         return strtr($template, array(
@@ -443,7 +442,7 @@ class rcube_kolab_contacts extends rcube_addressbook
         $this->filter = array('fields' => $fields, 'value' => $value, 'mode' => $mode, 'ids' => array());
 
         // search by iterating over all records in dataset
-        foreach ($this->dataset as $i => $record) {
+        foreach ($this->dataset as $record) {
             $contact = $this->_to_rcube_contact($record);
             $id = $contact['ID'];
 
diff --git a/plugins/kolab_auth/kolab_auth.php b/plugins/kolab_auth/kolab_auth.php
index ebe923d4..033d5b17 100644
--- a/plugins/kolab_auth/kolab_auth.php
+++ b/plugins/kolab_auth/kolab_auth.php
@@ -88,8 +88,6 @@ class kolab_auth extends rcube_plugin
      */
     public function startup($args)
     {
-        $rcmail = rcube::get_instance();
-
         // Check access rights when logged in as another user
         if (!empty($_SESSION['kolab_auth_admin']) && $args['task'] != 'login' && $args['task'] != 'logout') {
             // access to specified task is forbidden,
diff --git a/plugins/kolab_auth/kolab_auth_ldap.php b/plugins/kolab_auth/kolab_auth_ldap.php
index 97844270..81af79b1 100644
--- a/plugins/kolab_auth/kolab_auth_ldap.php
+++ b/plugins/kolab_auth/kolab_auth_ldap.php
@@ -57,8 +57,6 @@ class kolab_auth_ldap extends rcube_ldap_generic
     */
     private function _connect()
     {
-        $rcube = rcube::get_instance();
-
         // try to connect + bind for every host configured
         // with OpenLDAP 2.x ldap_connect() always succeeds but ldap_bind will fail if host isn't reachable
         // see http://www.php.net/manual/en/function.ldap-connect.php
diff --git a/plugins/kolab_config/kolab_config.php b/plugins/kolab_config/kolab_config.php
index 60fc4cf2..ef9d09a4 100644
--- a/plugins/kolab_config/kolab_config.php
+++ b/plugins/kolab_config/kolab_config.php
@@ -30,7 +30,6 @@ class kolab_config extends rcube_plugin
 {
     public $task = 'utils';
 
-    private $enabled;
     private $config;
     private $dicts = array();
 
diff --git a/plugins/kolab_delegation/kolab_delegation_engine.php b/plugins/kolab_delegation/kolab_delegation_engine.php
index e346b10e..b5dc7599 100644
--- a/plugins/kolab_delegation/kolab_delegation_engine.php
+++ b/plugins/kolab_delegation/kolab_delegation_engine.php
@@ -67,7 +67,6 @@ class kolab_delegation_engine
         }
 
         $list = $this->list_delegates();
-        $user = $this->user();
 
         // add delegate to the list
         $list = array_keys((array)$list);
@@ -448,7 +447,7 @@ class kolab_delegation_engine
             // sort users index
             asort($keys, SORT_LOCALE_STRING);
             // re-sort users according to index
-            foreach ($keys as $idx => $val) {
+            foreach (array_keys($keys) as $idx) {
                 $keys[$idx] = $users[$idx];
             }
             $users = array_values($keys);
diff --git a/plugins/kolab_files/lib/kolab_files_engine.php b/plugins/kolab_files/lib/kolab_files_engine.php
index 0c01ce66..36f93abf 100644
--- a/plugins/kolab_files/lib/kolab_files_engine.php
+++ b/plugins/kolab_files/lib/kolab_files_engine.php
@@ -463,7 +463,7 @@ class kolab_files_engine
             $inner   = $this->rc->gettext('listoptions');
 
             if (is_string($attrib['optionsmenuicon']) && $attrib['optionsmenuicon'] != 'true') {
-                $inner = html::img(array('src' => $skin_path . $attrib['optionsmenuicon'], 'alt' => $RCMAIL->gettext('listoptions')));
+                $inner = html::img(array('src' => $skin_path . $attrib['optionsmenuicon'], 'alt' => $this->rc->gettext('listoptions')));
             }
 
             $list_menu = html::a(array(
diff --git a/plugins/kolab_notes/kolab_notes.php b/plugins/kolab_notes/kolab_notes.php
index 4def1214..c2b4945c 100644
--- a/plugins/kolab_notes/kolab_notes.php
+++ b/plugins/kolab_notes/kolab_notes.php
@@ -893,7 +893,7 @@ class kolab_notes extends rcube_plugin
         if (!empty($args['param']['with_notes'])) {
             $uids = explode(',', $args['param']['with_notes']);
             $list = $args['param']['notes_list'];
-            $attachments = array();
+
             foreach ($uids as $uid) {
                 if ($note = $this->get_note(array('uid' => $uid, 'list' => $list))) {
                     $args['attachments'][] = array(
diff --git a/plugins/kolab_tags/lib/kolab_tags_engine.php b/plugins/kolab_tags/lib/kolab_tags_engine.php
index 4cf02dee..52013c8b 100644
--- a/plugins/kolab_tags/lib/kolab_tags_engine.php
+++ b/plugins/kolab_tags/lib/kolab_tags_engine.php
@@ -154,7 +154,7 @@ class kolab_tags_engine
 
             // ...filter members by folder/uid prefix
             foreach ((array) $tag['members'] as $idx => $member) {
-                foreach ($filter as $folder => $members) {
+                foreach ($filter as $members) {
                     // list of prefixes
                     if (is_array($members)) {
                         foreach ($members as $message) {
diff --git a/plugins/libcalendaring/lib/libcalendaring_itip.php b/plugins/libcalendaring/lib/libcalendaring_itip.php
index bd83f163..2ba15478 100644
--- a/plugins/libcalendaring/lib/libcalendaring_itip.php
+++ b/plugins/libcalendaring/lib/libcalendaring_itip.php
@@ -353,7 +353,7 @@ class libcalendaring_itip
         if ($existing) {
           $rsvp = $event['rsvp'];
           $emails = $this->lib->get_user_emails();
-          foreach ($existing['attendees'] as $i => $attendee) {
+          foreach ($existing['attendees'] as $attendee) {
             if ($attendee['email'] && in_array(strtolower($attendee['email']), $emails)) {
               $status = strtoupper($attendee['status']);
               break;
diff --git a/plugins/libcalendaring/libvcalendar.php b/plugins/libcalendaring/libvcalendar.php
index 062ee7e7..b94ceed9 100644
--- a/plugins/libcalendaring/libvcalendar.php
+++ b/plugins/libcalendaring/libvcalendar.php
@@ -318,7 +318,7 @@ class libvcalendar implements Iterator
                     if (!$seen[$object['uid']]++) {
                         // parse recurrence exceptions
                         if ($object['recurrence']) {
-                            foreach ($vobject->children as $i => $component) {
+                            foreach ($vobject->children as $component) {
                                 if ($component->name == 'VEVENT' && isset($component->{'RECURRENCE-ID'})) {
                                     $object['recurrence']['EXCEPTIONS'][] = $this->_to_array($component);
                                 }
@@ -391,7 +391,6 @@ class libvcalendar implements Iterator
         }
 
         // map other attributes to internal fields
-        $_attendees = array();
         foreach ($ve->children as $prop) {
             if (!($prop instanceof VObject\Property))
                 continue;
@@ -857,7 +856,6 @@ class libvcalendar implements Iterator
      */
     public function export($objects, $method = null, $write = false, $get_attachment = false, $with_timezones = true)
     {
-        $memory_limit = parse_bytes(ini_get('memory_limit'));
         $this->method = $method;
 
         // encapsulate in VCALENDAR container
@@ -1095,10 +1093,13 @@ class libvcalendar implements Iterator
         if ($event['comment'])
             $ve->add('COMMENT', $event['comment']);
 
+        $memory_limit = parse_bytes(ini_get('memory_limit'));
+
         // export attachments
         if (!empty($event['attachments'])) {
             foreach ((array)$event['attachments'] as $attach) {
                 // check available memory and skip attachment export if we can't buffer it
+                // @todo: use rcube_utils::mem_check()
                 if (is_callable($get_attachment) && $memory_limit > 0 && ($memory_used = function_exists('memory_get_usage') ? memory_get_usage() : 16*1024*1024)
                     && $attach['size'] && $memory_used + $attach['size'] * 3 > $memory_limit) {
                     continue;
diff --git a/plugins/libkolab/lib/kolab_bonnie_api.php b/plugins/libkolab/lib/kolab_bonnie_api.php
index 23dafd82..e8ac131d 100644
--- a/plugins/libkolab/lib/kolab_bonnie_api.php
+++ b/plugins/libkolab/lib/kolab_bonnie_api.php
@@ -36,7 +36,7 @@ class kolab_bonnie_api
      */
     public function __construct($config)
     {
-        $this->config = $confg;
+        $this->config = $config;
 
         $this->client = new kolab_bonnie_api_client($config['uri'], $config['timeout'] ?: 5, (bool)$config['debug']);
 
diff --git a/plugins/libkolab/lib/kolab_format_event.php b/plugins/libkolab/lib/kolab_format_event.php
index c233f444..da0e43a3 100644
--- a/plugins/libkolab/lib/kolab_format_event.php
+++ b/plugins/libkolab/lib/kolab_format_event.php
@@ -98,7 +98,7 @@ class kolab_format_event extends kolab_format_xcal
             $vexceptions = new vectorevent;
             foreach((array)$object['recurrence']['EXCEPTIONS'] as $exception) {
                 $exevent = new kolab_format_event;
-                $exevent->set($this->compact_exception($exception, $object));  // only save differing values
+                $exevent->set($this->compact_exception($exception));  // only save differing values
                 $exevent->obj->setRecurrenceID(self::get_datetime($exception['start'], null, true), (bool)$exception['thisandfuture']);
                 $vexceptions->push($exevent->obj);
             }
@@ -207,7 +207,7 @@ class kolab_format_event extends kolab_format_xcal
     /**
      * Remove some attributes from the exception container
      */
-    private function compact_exception($exception, $master)
+    private function compact_exception($exception)
     {
       $forbidden = array('recurrence','organizer','attendees','sequence');
 
diff --git a/plugins/libkolab/lib/kolab_storage.php b/plugins/libkolab/lib/kolab_storage.php
index dfd18877..3a70bd52 100644
--- a/plugins/libkolab/lib/kolab_storage.php
+++ b/plugins/libkolab/lib/kolab_storage.php
@@ -403,13 +403,13 @@ class kolab_storage
             'oldname' => $oldname, 'newname' => $newname));
 
         $oldfolder = self::get_folder($oldname);
-        $active = self::folder_is_active($oldname);
-        $success = self::$imap->rename_folder($oldname, $newname);
+        $active    = self::folder_is_active($oldname);
+        $success   = self::$imap->rename_folder($oldname, $newname);
         self::$last_error = self::$imap->get_error_str();
 
         // pass active state to new folder name
         if ($success && $active) {
-            self::set_state($oldnam, false);
+            self::set_state($oldname, false);
             self::set_state($newname, true);
         }
 
@@ -1086,7 +1086,7 @@ class kolab_storage
             return $types[self::CTYPE_KEY_PRIVATE];
         }
         else if (!empty($types[self::CTYPE_KEY])) {
-            list($ctype, $suffix) = explode('.', $types[self::CTYPE_KEY]);
+            list($ctype, ) = explode('.', $types[self::CTYPE_KEY]);
             return $ctype;
         }
         return null;
@@ -1464,7 +1464,7 @@ class kolab_storage
         $user_attrib = self::$config->get('kolab_users_id_attrib', self::$config->get('kolab_auth_login', 'mail'));
 
         array_walk($results, function(&$user, $dn) use ($root, $user_attrib) {
-            list($localpart, $domain) = explode('@', $user[$user_attrib]);
+            list($localpart, ) = explode('@', $user[$user_attrib]);
             $user['kolabtargetfolder'] = $root . $localpart;
         });
 
diff --git a/plugins/libkolab/lib/kolab_storage_cache.php b/plugins/libkolab/lib/kolab_storage_cache.php
index 89f650d2..6f222520 100644
--- a/plugins/libkolab/lib/kolab_storage_cache.php
+++ b/plugins/libkolab/lib/kolab_storage_cache.php
@@ -431,7 +431,7 @@ class kolab_storage_cache
     /**
      * Remove all objects from local cache
      */
-    public function purge($type = null)
+    public function purge()
     {
         if (!$this->ready) {
             return true;
diff --git a/plugins/libkolab/lib/kolab_storage_folder.php b/plugins/libkolab/lib/kolab_storage_folder.php
index 59d407ff..d33f9d07 100644
--- a/plugins/libkolab/lib/kolab_storage_folder.php
+++ b/plugins/libkolab/lib/kolab_storage_folder.php
@@ -360,7 +360,7 @@ class kolab_storage_folder extends kolab_storage_folder_api
                         $object['_formatobj']->get_attachments($object);
                     }
 
-                    foreach ($object['_attachments'] as $k => $attach) {
+                    foreach ($object['_attachments'] as $attach) {
                         if ($attach['id'] == $part) {
                             if ($print)   echo $attach['content'];
                             else if ($fp) fwrite($fp, $attach['content']);
@@ -882,7 +882,7 @@ class kolab_storage_folder extends kolab_storage_folder_api
         if (!empty($object['_attachments']) && ($mem_limit = parse_bytes(ini_get('memory_limit'))) > 0) {
             $memory = function_exists('memory_get_usage') ? memory_get_usage() : 16*1024*1024; // safe value: 16MB
 
-            foreach ($object['_attachments'] as $id => $attachment) {
+            foreach ($object['_attachments'] as $attachment) {
                 $memory += $attachment['size'];
             }
 
diff --git a/plugins/tasklist/drivers/kolab/tasklist_kolab_driver.php b/plugins/tasklist/drivers/kolab/tasklist_kolab_driver.php
index be51d236..e94565e8 100644
--- a/plugins/tasklist/drivers/kolab/tasklist_kolab_driver.php
+++ b/plugins/tasklist/drivers/kolab/tasklist_kolab_driver.php
@@ -92,7 +92,7 @@ class tasklist_kolab_driver extends tasklist_driver
         $prefs = $this->rc->config->get('kolab_tasklists', array());
 
         foreach ($folders as $folder) {
-            $tasklist = $this->folder_props($folder, $delim, $prefs);
+            $tasklist = $this->folder_props($folder, $prefs);
 
             $this->lists[$tasklist['id']] = $tasklist;
             $this->folders[$tasklist['id']] = $folder;
@@ -103,7 +103,7 @@ class tasklist_kolab_driver extends tasklist_driver
     /**
      * Derive list properties from the given kolab_storage_folder object
      */
-    protected function folder_props($folder, $delim, $prefs)
+    protected function folder_props($folder, $prefs)
     {
         if ($folder->get_namespace() == 'personal') {
             $norename = false;
@@ -179,7 +179,7 @@ class tasklist_kolab_driver extends tasklist_driver
 
         $lists = array();
         foreach ($folders as $folder) {
-            $list_id = $folder->id; #kolab_storage::folder_id($folder->name);
+            $list_id   = $folder->id; // kolab_storage::folder_id($folder->name);
             $imap_path = explode($delim, $folder->name);
 
             // find parent
@@ -225,7 +225,7 @@ class tasklist_kolab_driver extends tasklist_driver
             }
             else {
                 if (!$this->lists[$list_id]) {
-                    $this->lists[$list_id] = $this->folder_props($folder, $delim, $prefs);
+                    $this->lists[$list_id] = $this->folder_props($folder, $prefs);
                     $this->folders[$list_id] = $folder;
                 }
                 $this->lists[$list_id]['parent'] = $parent_id;
@@ -249,7 +249,7 @@ class tasklist_kolab_driver extends tasklist_driver
             $folder = kolab_storage::get_folder(kolab_storage::id_decode($id));
             if ($folder->type) {
                 $this->folders[$id] = $folder;
-                $this->lists[$id] = $this->folder_props($folder, $this->rc->get_storage()->get_hierarchy_delimiter(), $this->rc->config->get('kolab_tasklists', array()));
+                $this->lists[$id] = $this->folder_props($folder, $this->rc->config->get('kolab_tasklists', array()));
             }
         }
 
@@ -295,7 +295,7 @@ class tasklist_kolab_driver extends tasklist_driver
         }
         else {
             $folder = kolab_storage::get_folder($folder);
-            $prop += $this->folder_props($folder, $this->rc->get_storage()->get_hierarchy_delimiter(), array());
+            $prop += $this->folder_props($folder, array());
         }
 
         return $id;
@@ -413,13 +413,11 @@ class tasklist_kolab_driver extends tasklist_driver
         $this->search_more_results = false;
         $this->lists = $this->folders = array();
 
-        $delim = $this->rc->get_storage()->get_hierarchy_delimiter();
-
         // find unsubscribed IMAP folders that have "event" type
         if ($source == 'folders') {
             foreach ((array)kolab_storage::search_folders('task', $query, array('other')) as $folder) {
                 $this->folders[$folder->id] = $folder;
-                $this->lists[$folder->id] = $this->folder_props($folder, $delim, array());
+                $this->lists[$folder->id] = $this->folder_props($folder, array());
             }
         }
         // search other user's namespace via LDAP
@@ -435,11 +433,11 @@ class tasklist_kolab_driver extends tasklist_driver
                 if (count($folders)) {
                     $userfolder = new kolab_storage_folder_user($user['kolabtargetfolder'], '', $user);
                     $this->folders[$userfolder->id] = $userfolder;
-                    $this->lists[$userfolder->id] = $this->folder_props($userfolder, $delim, array());
+                    $this->lists[$userfolder->id] = $this->folder_props($userfolder, array());
 
                     foreach ($folders as $folder) {
                         $this->folders[$folder->id] = $folder;
-                        $this->lists[$folder->id] = $this->folder_props($folder, $delim, array());
+                        $this->lists[$folder->id] = $this->folder_props($folder, array());
                         $count++;
                     }
                 }
diff --git a/plugins/tasklist/tasklist.php b/plugins/tasklist/tasklist.php
index 3f23c599..b39e78a6 100644
--- a/plugins/tasklist/tasklist.php
+++ b/plugins/tasklist/tasklist.php
@@ -1605,7 +1605,7 @@ class tasklist extends rcube_plugin
     /**
      * Resolve the email message reference from the given URI
      */
-    public function get_message_reference($uri, $resolve = false)
+    public function get_message_reference($uri)
     {
         if (strpos($uri, 'imap:///') === 0) {
             $url = parse_url(substr($uri, 8));
@@ -1657,7 +1657,7 @@ class tasklist extends rcube_plugin
 
         if ($uid && $mime_id) {
             $part    = $imap->get_message_part($uid, $mime_id);
-            $headers = $imap->get_message_headers($uid);
+//            $headers = $imap->get_message_headers($uid);
 
             if ($part->ctype_parameters['charset']) {
                 $charset = $part->ctype_parameters['charset'];