mx.gansend.com has no CNAME records.
Question and response
Question
dig mx.gansend.com. NS
Answer
The response has no answer records.
Authority
gansend.com. 3408 SOA ns1.mainloop.net. hostmaster.gansend.com. 2025080606 3600 900 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0