spf-0.secureserver.net has no MX records.
Question and response
Question
dig spf-0.secureserver.net. MX
Answer
The response has no answer records.
Authority
secureserver.net. 3600 SOA cns1.secureserver.net. dns.jomax.net. 2026022012 300 600 1209600 3600
Additional
. 0 OPT ; payload 1280, xrcode 0, version 0, flags 0