poczta.netbis.pl has no MX records.
Question and response
Question
dig poczta.netbis.pl. MX
Answer
The response has no answer records.
Authority
netbis.pl. 60 SOA dns102.ovh.net. tech.ovh.net. 2026020500 86400 3600 3600000 60
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0