mx01.tophost.ch has no CNAME records.
Question and response
Question
dig mx01.tophost.ch. NS
Answer
The response has no answer records.
Authority
tophost.ch. 2928 SOA ns59.tophost.ch. admin.novatrend.ch. 2026030932 3600 1800 1209600 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0