u17235485.wl236.sendgrid.net has no NS records.
NS records for this zone are defined at wl236.sendgrid.net.
NS records for this zone are defined at wl236.sendgrid.net.
Question and response
Question
dig u17235485.wl236.sendgrid.net. NS
Answer
The response has no answer records.
Authority
wl236.sendgrid.net. 1800 SOA aisha.ns.cloudflare.com. dns.cloudflare.com. 2399348615 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0