mandrillspf.avbuyer.com has no NS records.
NS records for this zone are defined at avbuyer.com.
NS records for this zone are defined at avbuyer.com.
Question and response
Question
dig mandrillspf.avbuyer.com. NS
Answer
The response has no answer records.
Authority
avbuyer.com. 1800 SOA tara.ns.cloudflare.com. dns.cloudflare.com. 2398381815 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0