gateway.spamcleaner.ch has no MX records.
Question and response
Question
dig gateway.spamcleaner.ch. MX
Answer
The response has no answer records.
Authority
spamcleaner.ch. 1800 SOA ns1.arcade.ch. technik.arcade.ch. 2026022601 10800 3600 2419200 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0