u2206867.wl118.sendgrid.net has no NS records.
NS records for this zone are defined at wl118.sendgrid.net.
NS records for this zone are defined at wl118.sendgrid.net.
Question and response
Question
dig u2206867.wl118.sendgrid.net. NS
Answer
The response has no answer records.
Authority
wl118.sendgrid.net. 1800 SOA aisha.ns.cloudflare.com. dns.cloudflare.com. 2399366624 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0