iptables: How to redirect / forward traffic without traffic through server?

view story

http://serverfault.com – I now played around with iptables (the whole day) to make my rules work, but there is one issue.. all traffic that I redirect goes through my server and back through my server. We are talking about high HIGH amounth of bandwidth. So I hoped there was a option to redirect a user to the external global IP, so it talkes to the external IP and the users IP directly. I now did: iptables -t nat -A PREROUTING -p tcp --dport 25 -j DNAT --to-destination iptables -t nat -A POSTROUTING -j MASQUERADE But now all traffic goes like this User>MyServer>ExternalServer>MyServer>User but i (HowTos)