u1916451.wl202.sendgrid.net has no NS records.
NS records for this zone are defined at wl202.sendgrid.net.
NS records for this zone are defined at wl202.sendgrid.net.
Question and response
Question
dig u1916451.wl202.sendgrid.net. NS
Answer
The response has no answer records.
Authority
wl202.sendgrid.net. 1800 SOA aisha.ns.cloudflare.com. dns.cloudflare.com. 2399107555 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0