Sonicwall Pro NAT

I just installed a SonicWall for our server environment. While most of the traffic is inbound, we do operate an email server that both sends and receives email. I was surprised to discover that this server appears to the world to be sending mail on the firewall's address. Inbound mail is accepted on it's native address. This is causing problems with reverse DNS configuration.

In our current configuration we are using the IP addresses provided by our ISP on the servers so we didn't configure NAT. So if this server has a native address of say, I want outbound mail to be coming from that address rather than, the address of the firewall.

Can anyone help me to configure the Sonicwall to accomplish this? Do I need a NAT rule that translates to


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Coupla things:

What type of sonicwall is it? There was a device calle the "sonicwall pro", but they stopped making that about 4 years ago or so, and since you just installed it... Is it a newer series, which all have a number: pro 2040, pro 3060, etc? or slightly older:pro 200, pro 230? What type and rev firware?

You say mail is accepted for the server on, but is going out via, which is the sonicwalls address.

How do you have the server connected here? You say "" is the "native address" of the server. I assume it only has one interface and is behind the sonicwall? which means you are using a "transparent mode" DMZ?

Or are you doing something like having two interfaces in the mail server, one for the internal and one for the external (BAD IDEA! - people get to confoozed as to how the routing works then)

Need more info - your setup is not clear.

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I am a Sock Puppet

Thanks for the follow-up questions. We are using an older SonicWall Pro. It had been sitting in a box for some time.

I changed the IP addresses (to protect the innocent) in the last note. I'll use different ones this time but they will more accurately reflect what is going on.

The LAN address of the firewall is: with a mask of The mail server has only one interface and is behind the sonicwall. It's address is with a mask of It's gateway is the LAN address of the firewall,

The WAN/DMZ address of the firewall is with a mask of

The server is sending and receiving using it's own address, But to the world it appears that messages are being sent from the WAN address of the sonicwall, That's what I'm trying to overcome. I'd like the server to be behind the firewall but send and receive using it's .201 address so that I can properly configure forward and reverse lookup.

Thanks again.


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