cl1.mescal.pl has no MX records.
Question and response
Question
dig cl1.mescal.pl. MX
Answer
The response has no answer records.
Authority
mescal.pl. 3600 SOA ns1.nazwa.pl. biuro.nazwa.pl. 2008133202 28800 7200 604800 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0