chr.nrnet.pl has no MX records.
Question and response
Question
dig chr.nrnet.pl. MX
Answer
The response has no answer records.
Authority
nrnet.pl. 1200 SOA dns1.mydevil.net. admin.admin.net.pl. 2025130011 10800 3600 604800 10800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0