_spfblock2.newsletter.ie has no NS records.
NS records for this zone are defined at newsletter.ie.
NS records for this zone are defined at newsletter.ie.
Question and response
Question
dig _spfblock2.newsletter.ie. NS
Answer
The response has no answer records.
Authority
newsletter.ie. 3600 SOA ns1.blacknight.com. hostmaster.blacknight.com. 1276145799 14400 7200 2419200 3600
Additional
. 0 OPT ; payload 1280, xrcode 0, version 0, flags 0