Apex domains cannot have CNAME records.
Question and response
Question
dig spf.infracom.se. NS
Answer
spf.infracom.se. 5 NS lurvas.infracom.se.
spf.infracom.se. 5 NS skalman.infracom.se.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0