mx1.pins-web.net has one IP number , which also has a corresponding reverse pointer. smtp.pins.nl cnames to this hostname. mx2.premiumdns.nl, pop.bluemining.com and mail2.hetdolhuys.nl point to the same IP. so.nl, 3-x.nl, ndw.nl, hub.nl, seh.nl and at least 100 other hosts use this as a mailserver. pins-web.net is delegated to two nameservers, however one extra nameserver is listed in the zone. All nameservers are at pins.nl. Two of them are on the same IP network. Incoming mail for pins-web.net is handled by two mailservers having a total of two IP numbers. There are two duplicated IP numbers. Some of them are on the same IP network. mx1.pins-web.net is hosted on a server in Netherlands.