cdptpa-postmx01.mail.rr.com has one IP number , which also has a corresponding reverse pointer. rr.com, buffalo.rr.com and postmaster.rr.com use this as a mailserver. mail.rr.com is a domain controlled by four nameservers at mail.rr.com themselves. Some of them are on the same IP network. Incoming mail for mail.rr.com is handled by six mailservers having a total of two IP numbers. There are ten duplicated IP numbers. Some of them are on the same IP network. cdptpa-postmx01.mail.rr.com is hosted on a server in United States.