_spf.iomartcloud.com has no CNAME records.
Question and response
Question
dig _spf.iomartcloud.com. NS
Answer
The response has no answer records.
Authority
iomartcloud.com. 3600 SOA heracles.iomart.com. hostmaster.iomart.com. 2025100200 43200 1800 2419200 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0