mail.cdkmessaging.com has no NS records.
NS records for this zone are defined at cdkmessaging.com.
NS records for this zone are defined at cdkmessaging.com.
Question and response
Question
dig u19967175.wl176.sendgrid.net. NS
Answer
The response has no answer records.
Authority
wl176.sendgrid.net. 1800 SOA aisha.ns.cloudflare.com. dns.cloudflare.com. 2397387171 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0