mx.customizedurl.com has no NS records.
NS records for this zone are defined at customizedurl.com.
NS records for this zone are defined at customizedurl.com.
Question and response
Question
dig mx.customizedurl.com. NS
Answer
The response has no answer records.
Authority
customizedurl.com. 3600 SOA ns1.sarbacane-dns.com. abuse.sarbacane.com. 2026022302 21600 3600 86400 172800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0