s2.teliadns.com has no MX records.
Question and response
Question
dig s2.teliadns.com. MX
Answer
The response has no answer records.
Authority
teliadns.com. 3600 SOA s2.teliadns.com. backbone.telia.net. 8 3600 1800 3600000 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0