firma.bialnet.pl has no MX records.
Question and response
Question
dig firma.bialnet.pl. MX
Answer
The response has no answer records.
Authority
bialnet.pl. 3600 SOA bialnet.pl. admin.bialnet.pl. 2024012407 3600 3600 2592000 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0