spf-c.3bbmail.com has no MX records.
Question and response
Question
dig spf-c.3bbmail.com. MX
Answer
The response has no answer records.
Authority
3bbmail.com. 120 SOA ns1.3bb.co.th. hostmaster.3bbmail.com. 2026012902 10800 3600 604800 120
Additional
. 0 OPT ; payload 1220, xrcode 0, version 0, flags 0