ns2.polcom.com.pl has no MX records.
Question and response
Question
dig ns2.polcom.com.pl. MX
Answer
The response has no answer records.
Authority
polcom.com.pl. 900 SOA ns1.polcom.com.pl. dnsadmin.polcom.com.pl. 2026021801 10800 3600 1814400 10800
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0