b.mx.vrmailer1.com has no NS records.
NS records for this zone are defined at vrmailer1.com.
NS records for this zone are defined at vrmailer1.com.
Question and response
Question
dig b.mx.vrmailer1.com. NS
Answer
The response has no answer records.
Authority
vrmailer1.com. 1800 SOA demi.ns.cloudflare.com. dns.cloudflare.com. 2395210720 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0