cPanel/Plesk Issues

HI everyone,

We currently run a fortigate 100D and have a few Plesk and cPanel servers behind it. We've started noticing since changing everything to NAT that the IP addresses are getting confused.

Sometimes when a user logs in it identifies them as the internal gateway address and not their external address.

We're also having issues with email where two servers on the same network are showing the internal address and not the external IP's which causing email to bounce...

Has anyone see this before?