_spfblock1.bluarc.ca has no CNAME records.
Question and response
Question
dig _spfblock1.bluarc.ca. NS
Answer
The response has no answer records.
Authority
bluarc.ca. 525 SOA dns60.telus.com. dnsadmin2.telus.com. 2025070349 600 7200 3600000 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0