mail.zapurn.com has no NS records.
NS records for this zone are defined at zapurn.com.
NS records for this zone are defined at zapurn.com.
Question and response
Question
dig mail.zapurn.com. NS
Answer
The response has no answer records.
Authority
zapurn.com. 3601 SOA dns1.registrar-servers.com. hostmaster.registrar-servers.com. 1772533605 43200 3600 604800 3601
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0