Question and response
Question
dig mxdomain.qq.com. AAAA
Answer
mxdomain.qq.com. 600 CNAME mx3.qq.com.
mx3.qq.com. 600 AAAA 240d:c040:1:40:0:0:0:133
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0