ns1.volc-dns.net has no MX records.
Question and response
Question
dig ns1.volc-dns.net. MX
Answer
The response has no answer records.
Authority
volc-dns.net. 300 SOA ns1.bytedns.com. dnsadmin.bytedance.com. 2022111113 3600 1200 86400 300
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0