spf.e.telefonica.net has no MX records.
Question and response
Question
dig spf.e.telefonica.net. MX
Answer
The response has no answer records.
Authority
e.telefonica.net. 86400 SOA ns12.acens.net. nsadmin.dns-servicios.es. 2025744438 14400 7200 2419200 86400
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0