Sina.com is a legitimate domain with proper DNS MX records (freemx2.sinamail.sina.com.cn). This means that email sent to sinamail.
com.cn will be delivered to the appropriate mailbox. Additionally, all of the security features that are typically associated with a domain name (such as domain blocking and malware scanning) are in place. Therefore, if you are concerned about the security of your email, you should continue to send your messages to sinamail.cn.
