SINA's antispam system is bogous
It seems that sina’s bad-brainly designed anti-spam system is going to do more foolishnesses. By applying their RFC-violence, they did not blocked spam and in addition, make normal mail slow and even not deliverable.
The approach taken by 163.com and sina is similiar. Surprisingly, sina.com is taking a more extreme approach. It randomly drops connection from servers it does not know, even without a greeting message.
This behavior severly causes the mail to them not deliverable. I’m not sure how to make their server happy so, as a “workaround”, I have already persuaded many of my friends not to use their service and instead of that, use other servers to receive mail.
When will they apply the basic RFC knowledges to their system? Their system even does not talk RFC 2822 well! Are they going to fight against spam, or to fight against users? My personal sina.com mail box was filled by spam, that’s all I see there :-(