mx2.linevps.com has no NS records.
NS records for this zone are defined at linevps.com.
NS records for this zone are defined at linevps.com.
Question and response
Question
dig mx2.linevps.com. NS
Answer
The response has no answer records.
Authority
linevps.com. 1800 SOA ruth.ns.cloudflare.com. dns.cloudflare.com. 2398721302 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0