Outbound email traffic is using the public IP assigned to FW external interface

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Outbound email traffic is using the public IP assigned to FW external interface

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New user of PA Firewall here. I noticed that when we send out emails, the recipient is seeing that the email comes from the public IP which is assigned to the external interface of our PA firewall. Before moving to PA, we can see the public IP NATed to our email server. Is there any configuration we missed? Or is this how it should be?

Appreciate your help. Thanks!


L4 Transporter

Hi, were you using Check Point automatic NAT previously?

I've seen a couple of similar issues before - these were resolved by inserting an additional NAT rule just before the NAT rule that is catching your outbound SMTP traffic at the moment.  The new NAT rule can then translate just your outbound email server traffic to have the the required source address.



Hi Dave,

Thanks for your reply.

Previously we were using Watchguard. I am a bit confused with your recommendation (insert a NAT rule before the Mail Server NAT). What would be the rule's content? Sorry for the bummer question...


Source IP: YourMailServer

DestinationIP: Any

Source Translation

IP Type: ip-static

Translated address : PublicIPAddressYouWant

Bidirectional: yes

Destination translation: none

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