One of my users is targeted with about 100 emails a day that have ###@qq.com as the "From:" header. The sender host is never qq.com but something like szcfxx.com, virexchina.com, maxnetsys.com.cn, xuanruanjian.com, etc. etc. Almost all of these get stopped by RBL...spamcop.net and never get into my email system, but they show up in "Track Delivery" and clutter it up. The few that get through into my email system are trapped out by a spam filter, as they typically have a spam score between 15 and 30!
Anyone have any insight into this?