Region : UnitedKingdom

Model : Archer C7

Hardware Version : Not Clear

Firmware Version :

ISP :

We have an AC750 which is installed between the internet and our private LAN, on the LAN we run Exchange server and have created a forward for SMTP to it through the router, we never had any problems until we installed the new router, we suddenly found out we were being used as a relay, luckily our exchange server sends out through our main Mail server which stopped the outbound email, spent a long time trying to work out what was going on and then it struck me, the incoming IP address was being replaced with the IP address of the router, which is trusted, therefore the exchange server would relay the message, I tested this from another ip address structure and sure enough in the logs of the exchange server it showed at all times the connecting IP as the router IP, this was not so using our old wr1043nd put this back on and the ip address is now reported as the senders ip.

This is a big problem, am I missing something as I have never seen this behaviour before.

Regards Pete