function whitelist_delete($emails)
 {
     $this->_db_connect('w');
     foreach ($emails as $email) {
         $this->db->query("DELETE FROM " . $this->table_name . " WHERE " . $this->username_field . " = ?" . " AND " . $this->preference_field . " = ?" . " AND " . $this->value_field . " = ?;", $this->sa_user, sauserprefs::map_pref_name('whitelist_from'), $email);
     }
 }
 function whitelist_delete($user_id, $emails)
 {
     $this->_db_connect('w');
     foreach ($emails as $email) {
         $this->db->query("DELETE FROM `{$this->table_name}` WHERE `{$this->username_field}` = ? AND `{$this->preference_field}` = ? AND `{$this->value_field}` = ?;", $user_id, sauserprefs::map_pref_name('whitelist_from'), $email);
     }
 }