ns-a1.zc-dns.com has no MX records.
Question and response
Question
dig ns-a1.zc-dns.com. MX
Answer
The response has no answer records.
Authority
zc-dns.com. 3600 SOA ns-a1.conoha.io. hostmaster.conoha.io. 2021072901 1800 900 604800 3600
Additional
. 0 OPT ; payload 2800, xrcode 0, version 0, flags 0