dns12.se.telia.net has no MX records.
Question and response
Question
dig dns12.se.telia.net. MX
Answer
The response has no answer records.
Authority
se.telia.net. 300 SOA dns1.telia.com. backbone.telia.net. 2026022702 10800 3600 604800 300
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0