u285109.wl.sendgrid.net has no CNAME records.
Question and response
Question
dig u285109.wl.sendgrid.net. NS
Answer
The response has no answer records.
Authority
wl.sendgrid.net. 1800 SOA aisha.ns.cloudflare.com. dns.cloudflare.com. 2398158676 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0