mail.gmb.ro has one IP number , which also has a corresponding reverse pointer. mail.msc.ro, mail.col.ro, mail.bda.ro, mail.nmp.ro, mail.ciid.ro and at least 47 other hosts point to the same IP. gmb.ro use this as a mailserver. cezar.mail.gmb.ro are subdomains to this hostname. gmb.ro is a domain controlled by two nameservers at gmb.ro themselves. They are on different IP networks. Incoming mail for gmb.ro is handled by one mailserver also at gmb.ro. gmb.ro has one IP number. mail.gmb.ro is hosted on a server in Romania.