cn.service.netease.com has no MX records.
Question and response
Question
dig cn.service.netease.com. MX
Answer
The response has no answer records.
Authority
netease.com. 60 SOA ns4.nease.net. admin.nease.net. 20810003 7200 1800 1209600 60
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0