Exchange Server 2003

Hi freinds , i m facing some problems , so i want to discuss with you. Our compnay have a inhouse mail server on linux in china our mail addrees is like “@company.com” we rae in INDIA we want to setup a exchange server who fecth mail from china server and send mail directly to recipients, the from and reply to address contain the same usernaem id @company.com

may i know hot is is posible, i try exchange pop it able to fecth mail , but it send mail routed from china mail server

i want this :

incoming mail :::
china mail server —mail—->> Exchange server users

Outgoing mail : —–> excange server —– directly to recipients ( but from contain my existing mail id which is creted in china server )

Thanks in Adavance