smtp.tripletex.no has no CNAME records.
Question and response
Question
dig smtp.tripletex.no. NS
Answer
The response has no answer records.
Authority
tripletex.no. 3600 SOA ns1.hyp.net. hostmaster.domeneshop.no. 1772132408 14400 3600 1209600 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0