The networks seem to be connected, so can't you just configure a smtp-forwarder in your MTA configuration ? That would be easier I think.
I'd prefer just using iptables, so i can redirect when i need to..
There is no need to use multiport because you only DNAT 1 port : smtp. But that should not be a problem.
iptables -t nat -A OUTPUT -p tcp --dports smtp \ -j DNAT --to-destination 192.168.12.56
if I try it without the multiport option i get the following error..
[root@posjia0h01 root]# iptables -t nat -A OUTPUT -p tcp --dports smtp -j DNAT --to-destination 192.168.12.56 iptables v1.2.5: Unknown arg `--dports' Try `iptables -h' or 'iptables --help' for more information.
And no I dont have any rules blocking this from working as shown below, but would i need any iptables rules to make it work maybe? (like enable ipforwarding and maybe a forward rule, im not sure)
[root@prxsaa0z02 root]# iptables -L Chain INPUT (policy ACCEPT) target prot opt source destination
Chain FORWARD (policy ACCEPT) target prot opt source destination
Chain OUTPUT (policy ACCEPT) target prot opt source destination [root@prxsaa0z02 root]# iptables -L -t nat Chain PREROUTING (policy ACCEPT) target prot opt source destination
Chain POSTROUTING (policy ACCEPT) target prot opt source destination
Chain OUTPUT (policy ACCEPT) target prot opt source destination
