mail.h1-mail1.microhost.pl has no MX records.
Question and response
Question
dig mail.h1-mail1.microhost.pl. MX
Answer
The response has no answer records.
Authority
h1-mail1.microhost.pl. 2000 SOA ns1.microhost.pl. hostmaster.h1-mail1.microhost.pl. 2021120801 2000 3600 1209600 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0