Some users may not be able to send emails after installing the CSF Firewall application. This problem is more frequent among WordPress users. By configuring the outbound SMTP settings for CSF Firewall using WHM, you can resolve this issue and allow your server to send emails properly.

How to Do It

  1. Step 1: Log in to WHM

    Log in to your WHM root account.

  2. Step 2: Access Plugins

    Navigate to Plugins from the menu.

    WHM Plugins menu

  3. Step 3: Open ConfigServer Security & Firewall

    Click on ConfigServer Security & Firewall.

    ConfigServer Security & Firewall option

    The CSF application will open.

  4. Step 4: Access Firewall Configuration

    Select the csf tab and click the Firewall Configuration button in the csf - ConfigServer Firewall section.

    CSF Firewall Configuration button

    The ConfigServer Firewall's configuration interface will appear.

  5. Step 5: Disable SMTP Blocking

    Scroll down to the SMTP Settings section and click the Off switch for the SMTP_BLOCK field.

    SMTP_BLOCK setting turned off

  6. Step 6: Save Changes

    Scroll to the end of the page and click the Change button to save your changes.

  7. Step 7: Restart CSF

    Click the Restart csf+lfd button to reboot the CSF application and apply the changes.

    Restart csf+lfd button

    The CSF Firewall will no longer block outgoing SMTP traffic for your WHM/cPanel server.