_spf.qlmail.ch has no MX records.
Question and response
Question
dig _spf.qlmail.ch. MX
Answer
The response has no answer records.
Authority
qlmail.ch. 43200 SOA . admin.qlns.ch. 2025011401 21600 3600 604800 43200
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0