u1943382.wl133.sendgrid.net has no NS records.
NS records for this zone are defined at wl133.sendgrid.net.
NS records for this zone are defined at wl133.sendgrid.net.
Question and response
Question
dig u1943382.wl133.sendgrid.net. NS
Answer
The response has no answer records.
Authority
wl133.sendgrid.net. 1800 SOA aisha.ns.cloudflare.com. dns.cloudflare.com. 2399634285 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0