private.insite.com.br has one IP number , which also has a corresponding reverse pointer. mx3.insite.com.br point to the same IP. bibi.org use this as a mailserver. insite.com.br is a domain controlled by two nameservers at insite.com.br themselves. They are on different IP networks. Incoming mail for insite.com.br is handled by four mailservers also at insite.com.br. Two of them are on the same IP network. insite.com.br has one IP number. private.insite.com.br is hosted on a server in United States even though the hostname implies Brazil.