spf.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 spf.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