myhostname = domain.nev.hu
a PTR meg a DNS-ben van. Pl:
$ host mail.t-online.hu
mail.t-online.hu has address 84.2.46.3
mail.t-online.hu has address 84.2.44.3
$ host 84.2.46.3
3.46.2.84.in-addr.arpa domain name pointer mail.t-online.hu.
$ host 84.2.44.3
3.44.2.84.in-addr.arpa domain name pointer mail.t-online.hu.