mailer338178.mergeworld.com has no NS records.
NS records for this zone are defined at mergeworld.com.
NS records for this zone are defined at mergeworld.com.
Question and response
Question
dig mailer338178.mergeworld.com. NS
Answer
The response has no answer records.
Authority
mergeworld.com. 1800 SOA janet.ns.cloudflare.com. dns.cloudflare.com. 2399047803 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0