a.mx.vrmailer3.com has no NS records.
NS records for this zone are defined at vrmailer3.com.
NS records for this zone are defined at vrmailer3.com.
Question and response
Question
dig a.mx.vrmailer3.com. NS
Answer
The response has no answer records.
Authority
vrmailer3.com. 1800 SOA demi.ns.cloudflare.com. dns.cloudflare.com. 2396131319 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0