spf.worksmobile.com has no MX records.
Question and response
Question
dig spf.worksmobile.com. MX
Answer
The response has no answer records.
Authority
worksmobile.com. 180 SOA ns1.naver.com. webmaster.naver.com. 2026022601 21600 1800 1209600 180
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0