_spf.mexline.com has no MX records.
Question and response
Question
dig _spf.mexline.com. MX
Answer
The response has no answer records.
Authority
mexline.com. 600 SOA ns02.mexline.com. netmin.mexline.com. 2026020314 3600 3600 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0