spf.renater.fr has no MX records.
Question and response
Question
dig spf.renater.fr. MX
Answer
The response has no answer records.
Authority
renater.fr. 300 SOA ns1.renater.fr. hostmaster.renater.fr. 2016440564 21600 3600 3600000 172800
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0