s1._domainkey.syncedtool.com has no NS records.
NS records for this zone are defined at syncedtool.com.
NS records for this zone are defined at syncedtool.com.
Question and response
Question
dig s1.domainkey.u250297.wl048.sendgrid.net. NS
Answer
The response has no answer records.
Authority
wl048.sendgrid.net. 1800 SOA aisha.ns.cloudflare.com. dns.cloudflare.com. 2398526347 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0