_spf.kth.se has no MX records.
Question and response
Question
dig _spf.kth.se. MX
Answer
The response has no answer records.
Authority
kth.se. 1800 SOA a.ns.kth.se. hostmaster.kth.se. 2026022305 14400 900 604800 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0