spf.ymlp.com has no MX records.
Question and response
Question
dig spf.ymlp.com. MX
Answer
The response has no answer records.
Authority
ymlp.com. 900 SOA ns8.ymlp.com. info.ymlp.com. 2026012801 10800 3600 604800 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0