hide private ip in header

[Ramesh]

Hi List,


I
would like know to steps required to hide private ip address in postfix,
when we sent email, full header at recipient end shows client private
ip address and also shows public ip address of firewall instead of
public ip address of mail server. i have cross checked iptables nating
rules which are correct.

appreciate suggestion to resolve the issue even i have tried with 
domain_masqurade not successful


Thanks and Regards,
Ramesh