_spf.flowmailer.net has no CNAME records.
Question and response
Question
dig _spf.flowmailer.net. NS
Answer
The response has no answer records.
Authority
flowmailer.net. 50 SOA ns1.flowmailer.net. contact.flowmailer.net. 2026021901 3600 300 7200 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0