spf.zml0.com has no MX records.
Question and response
Question
dig spf.zml0.com. MX
Answer
The response has no answer records.
Authority
zml0.com. 300 SOA a2-66.akam.net. hostmaster.zdirect.com. 2016061114 3600 1800 172800 300
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0