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by anonymous


I have a RUT240 that flows as backup internet link. Also behind the RUT240 I have another Router/Firewall that flows like main Router that has got an Email SMTP server.

The tree is like this:

I have a configuration NAT in Router240 but, emails server detects always that the connection is from IP, and it must be client IP due to spam firewall and as a high volume of emails from "the same IP" are blocked:

(image 2)

How I have to configure Router240?

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by anonymous


I've inherited a SBS2008 server running exchange and for various reasons, need to run it (and its four users) behind a router within our network on a different subnet.

Our main router is a beefy mikrotik job, and at present, the exchange server is hooked up behind a cheap SOHO router (TP-Link or something).

Both routers are doing NAT. I've forwarded port 25 from outside to the LAN IP of the cheap router's WAN interface, and forwarded port 25 to the exchange server IP in the cheap router.

Running a SMTP test from outside (the internet), it appears that the server is responding OK. However until I change over the MX records, I can't test it or know for sure. We use google apps in our organisation so this shouldn't affect business as usual.

by anonymous

that's great! Runing double NAT, does Exchange server get the real IP of the client or gets the IP of the router? (because of SPAM detection). If the exchange gets the IP of the router could be a Security problem (And that's my main problem :( )