mail.csneng.com has one IP number , which is the same as for csneng.com, but no corresponding reverse pointer. 4h.co.th, rcgen.com, mws.ac.th, s-171.com, csneng.com and at least 65 other hosts point to the same IP. csneng.com use this as a mailserver. csneng.com is a domain controlled by three nameservers. Two nameservers have the same IP number. Some of them are on the same IP network. Incoming mail for csneng.com is handled by one mailserver at csneng.com themselves. mail.csneng.com is hosted on a server in Thailand.