polmail04.polcard.com.pl has no MX records.
Question and response
Question
dig polmail04.polcard.com.pl. MX
Answer
The response has no answer records.
Authority
polcard.com.pl. 300 SOA dns2.p07.nsone.net. domainadmin.firstdata.com. 590215820 1200 180 604800 300
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0