sto.excedodns.se has no MX records.
Question and response
Question
dig sto.excedodns.se. MX
Answer
The response has no answer records.
Authority
excedodns.se. 3600 SOA global.excedodns.com. hostmaster.excedo.se. 1767046000 43200 3600 604800 3600
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0