mx7.zoho.com has no NS records.
NS records for this zone are defined at zoho.com.
NS records for this zone are defined at zoho.com.
Question and response
Question
dig mx7.zoho.com. NS
Answer
The response has no answer records.
Authority
zoho.com. 300 SOA ns1.zohocorp.com. dnsadmin.vtitan.com. 2026022300 7200 1800 1209600 3600
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0