u22975747.wl248.sendgrid.net has no NS records.
NS records for this zone are defined at wl248.sendgrid.net.
NS records for this zone are defined at wl248.sendgrid.net.
Question and response
Question
dig u22975747.wl248.sendgrid.net. NS
Answer
The response has no answer records.
Authority
wl248.sendgrid.net. 1800 SOA aisha.ns.cloudflare.com. dns.cloudflare.com. 2399108309 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0