预热 逻辑

@@ -71,6 +71,7 @@ class HotMail {
             if(folderAlias($f['folder']) == $folder){
                 // 最后记录的id
                 $last_id = db()->value('select max(`lists_id`) from `fob_hot_mail` where `email_id` = '.$email_id.' limit 1');
+                $last_id = $last_id?$last_id:0;
                 $this->findList(new Data($email_id,$f['id'],$type,$last_id));
             }
         }