mail.fast.vn has one IP number , which is the same as for fast.vn, via cname. v000.com, htel.net, uzza.com, wh4u.com, tg4u.com and at least 100 other hosts point to the same IP. fast.vn is a domain controlled by two nameservers at cypack.com. They are on the same IP network. mail.fast.vn is hosted on a server in Korea even though the hostname implies Vietnam.