u2066549.wl.sendgrid.net has no SRV records.
Question and response
Question
dig u2066549.wl.sendgrid.net. SRV
Answer
The response has no answer records.
Authority
wl.sendgrid.net. 1800 SOA aisha.ns.cloudflare.com. dns.cloudflare.com. 2398331355 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0