a.mx.easystyle.org and b.mx.easystyle.org are subdomains to this hostname. easystyle.org is a domain controlled by two nameservers at easystyle.org themselves. They are on different IP networks. Incoming mail for easystyle.org is handled by seven mailservers having a total of 28 IP numbers. Some of them are on the same IP network. easystyle.org has one IP number.