mc.hichina.com has one IP number. syyy.net, nggs.net, zbht.com, 5840.net, bzsy.net and at least 100 other hosts use this as a mailserver. hichina.com is a domain controlled by two nameservers having a total of four IP numbers. Some of them are on the same IP network. Incoming mail for hichina.com is handled by two mailservers at hichina.com themselves. They are on different IP networks. hichina.com has one IP number. mc.hichina.com is hosted on a server in China.