clm.net4all.ch has no MX records.
Question and response
Question
dig clm.net4all.ch. MX
Answer
The response has no answer records.
Authority
clm.net4all.ch. 3600 SOA dns01.net4all-dns.com.clm.net4all.ch. hostmaster.net4all-dns.com. 2018101803 10800 3600 2592000 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0