spfmx.mediamid.com has no CNAME records.
Question and response
Question
dig spfmx.mediamid.com. NS
Answer
The response has no answer records.
Authority
mediamid.com. 7117 SOA ns1.gandi.net. hostmaster.gandi.net. 1772200115 10800 3600 604800 10800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0