spf.mailrelay3.com has no NS records.
NS records for this zone are defined at mailrelay3.com.
NS records for this zone are defined at mailrelay3.com.
Question and response
Question
dig spf.mailrelay3.com. NS
Answer
The response has no answer records.
Authority
mailrelay3.com. 3600 SOA mailrelay3.com.mailrelay3.com. root.mailrelay3.com.mailrelay3.com. 2039470413 7200 3600 86400 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0