spf-b.telia.com has no MX records.
Question and response
Question
dig spf-b.telia.com. MX
Answer
The response has no answer records.
Authority
telia.com. 3600 SOA dns1.telia.com. backbone.telia.net. 2026013001 10800 3600 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0