u25135829.wl080.sendgrid.net has no NS records.
NS records for this zone are defined at wl080.sendgrid.net.
NS records for this zone are defined at wl080.sendgrid.net.
Question and response
Question
dig u25135829.wl080.sendgrid.net. NS
Answer
The response has no answer records.
Authority
wl080.sendgrid.net. 1800 SOA aisha.ns.cloudflare.com. dns.cloudflare.com. 2399377218 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0