mail.byteheavy.com has no NS records.
NS records for this zone are defined at byteheavy.com.
NS records for this zone are defined at byteheavy.com.
Question and response
Question
dig smtp.byteheavy.com. NS
Answer
The response has no answer records.
Authority
byteheavy.com. 86400 SOA ns1.he.net. hostmaster.he.net. 2025102401 10800 1800 604800 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0