eduproxy17953.mail.163.com has no MX records.
Question and response
Question
dig eduproxy17953.mail.163.com. MX
Answer
The response has no answer records.
Authority
163.com. 60 SOA ns4.nease.net. admin.nease.net. 20292011 7200 1800 1209600 60
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0