Email routed internally appears to come from router IP

[sagelike]

Hi there,

I am having a problem with email routed internally and directly to our email server. All internally routed email appears to come from the router IP which is making it harder to configure router for allowed relay.

I was having same problem with external email but once I disabled NAT, external email began showing the originating IP.

The Internal wan1 interface has NAT enabled.My questions are:

If I disabled NAT for Internal wan1, will this allow internally routed email to correctly resolve IP?

If I disabled NAT for Internal wan1, what side effects or problems might arise from that?

Thanks in advance.

G

[ede_pfau]

NAT should not be enabled in that policy at all.

Without NAT, the source IP address of traffic arriving at the FGT ('router') will not be changed. If that poses a problem in your network setup or not can only be answered by you.

One possible situation would be that there is reply traffic to the source. As the source is an arbitrary IP address the device will need to have a default route pointing to your WAN.

[sagelike]

Thanks Ede. I will try disabling NAT for Internal. I just wanted to be sure that is how it should be configured and I don't believe it will cause any problems but you never know.

[ede_pfau]

Either try it out, you'll notice quickly...or have a look at your network design. This is quite predictable IMHO.