mail.updatesystem.se has no CNAME records.
Question and response
Question
dig mail.updatesystem.se. NS
Answer
The response has no answer records.
Authority
updatesystem.se. 1673 SOA ns1.loopia.se. registry.loopia.se. 1771459200 14400 3600 604800 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0