smtp.ipartners.pl has no MX records.
Question and response
Question
dig smtp.ipartners.pl. MX
Answer
The response has no answer records.
Authority
ipartners.pl. 86400 SOA ns1.ikp.pl. hostmaster.ikp.pl. 2026021900 10800 3600 3600000 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0