ns2.net.edu.cn has no MX records.
Question and response
Question
dig ns2.net.edu.cn. MX
Answer
The response has no answer records.
Authority
net.edu.cn. 600 SOA ns2.net.edu.cn. hostmaster.dns.edu.cn. 1996022899 7200 1800 604800 600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0