ns.gabia.net has no MX records.
Question and response
Question
dig ns.gabia.net. MX
Answer
The response has no answer records.
Authority
ns.gabia.net. 86400 SOA ns.gabia.co.kr. hosting.gabia.com. 2023051821 1800 600 1209600 86400
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0