s2._domainkey.axcient.com has no NS records.
NS records for this zone are defined at axcient.com.
NS records for this zone are defined at axcient.com.
Question and response
Question
dig s2.domainkey.u23552801.wl052.sendgrid.net. NS
Answer
The response has no answer records.
Authority
wl052.sendgrid.net. 1800 SOA aisha.ns.cloudflare.com. dns.cloudflare.com. 2398994289 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0