Sohu, one of the biggest ISPs in China, offers also anti-spam support.
Here you can find out all bounce codes from sohu
http://mail.sohu.com/info/policy/
and here you can look up your IPs, if they are blacklisted by sohu
http://mail.sohu.com/info/queryip/
and as well as IP look up, you can check out the blocked sender domains here
http://mail.sohu.com/info/querysender/
if you have more questions, plz contact the support center under
Email: webmaster@vip.sohu.com or Hotline: +86-(0)10-58511234
Have fun by anti-spamming!
