When deploying a Barracuda Email Security Gateway behind the Barracuda NextGen Firewall X-Series, configure a Destination NAT (DNAT) access rule to route SMTP traffic to the Email Security Gateway. For more information on the Barracuda Email Security Gateway, see: Overview.
This article provides instructions on how to configure an access rule for the following setup:
Before you Begin
Install and configure the Barracuda Email Security Gateway in your LAN as described in: Deployment Behind the Corporate Firewall.
Step 1. (Optional) Create a Service Object for SMTPS
To also forward SMTPS traffic to your Email Security Gateway, create a service object to redirect the traffic to port 465. For more information, see Service Objects.
Use the following settings:
- Protocol – TCP
- Port Range – 465
Step 2. Configure a DNAT Access Rule
Create a DNAT access rule that forwards all incoming SMTP traffic to the IP address of the Email Security Gateway.
- Go to the FIREWALL > Firewall Rules page.
- Click Add Access Rule to create a new firewall rule.
- In the Add Access Rule window, enter a name and description for the rule.
Specify the following settings:
Action Connection Source Network Services Destination Redirected To DNAT No SNAT Internet SMTP, SMTP SSL (optional) Enter the public IP address of the X-Series Firewall. E.g.:
Enter the IP address or select the network object for your Barracuda Email Security Gateway. E.g.:
- Click Save.
Step 2. Verify the Order of the Access Rules
Because rules are processed from top to bottom in the rule set, arrange your access rules in the correct order. Make sure that this rule is the first access rule that matches SMTP traffic on the WAN port of the X-Series Firewall.
After adjusting the order of the rules in the rule set, click Save.