ns1.swiss-dns.com has no MX records.
Question and response
Question
dig ns1.swiss-dns.com. MX
Answer
The response has no answer records.
Authority
swiss-dns.com. 86400 SOA ns1.swiss-server.net. hostmaster.swiss-dns.com. 2022051106 10800 3600 604800 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0