mail2.nethry.eu has one IP number , but the reverse is b19.banan.cz. ivl.cz, banan.it, vivat.cz, ovsem.net, mail2.un.cz and at least 100 other hosts point to the same IP. nethry.eu use this as a mailserver. nethry.eu is a domain controlled by three nameservers. Two of them are on the same IP network. Incoming mail for nethry.eu is handled by two mailservers at nethry.eu themselves. They are on the same IP network. nethry.eu has one IP number. mail2.nethry.eu is hosted on a server in Czech Republic even though the hostname implies Europe.