mail2.netnod.se has no CNAME records.
Question and response
Question
dig mail2.netnod.se. NS
Answer
The response has no answer records.
Authority
netnod.se. 2835 SOA nna.netnod.se. noc.netnod.se. 1772729579 7200 1800 604800 7200
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0