mail.psew.pl has one IP number , which is the same as for psew.pl, but no corresponding reverse pointer. psew.pl, pwea.pl, myinet.pl, psew.org.pl, mail.bic.pl and at least 100 other hosts point to the same IP. psew.pl use this as a mailserver. psew.pl is a domain controlled by two nameservers at myinet.pl. They are on the same IP network. Incoming mail for psew.pl is handled by one mailserver at psew.pl themselves. mail.psew.pl is hosted on a server in Poland.