s1._domainkey.itassist.eu has no NS records.
NS records for this zone are defined at itassist.eu.
NS records for this zone are defined at itassist.eu.
Question and response
Question
dig s1.domainkey.u27364308.wl059.sendgrid.net. NS
Answer
The response has no answer records.
Authority
wl059.sendgrid.net. 1800 SOA aisha.ns.cloudflare.com. dns.cloudflare.com. 2400346273 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0