How to stop Spam attacks on cPanel hosting server

This article explains how to stop Spam attacks on cPanel hosting server.

Linux’s open-source nature attracts both a strong community and potential threats. To secure cPanel servers from spam and attacks, implementing robust security measures is essential.

Here’s how you can do it:

Configure the Exim Mail Server:
1. Log in to WHM
  Access the WHM control panel using your root login credentials.
2. Access Exim Configuration Manager
  Navigate to Service Configuration and select Exim Configuration Manager.
3. Enable RBL Filtering
  In the Basic Editor, turn the RBLs switch to On. Optionally, you can add additional RBLs using the “Manage” option.
4. Enable Sender Verification
  - Turn Sender Verification Callouts to On.
  - Turn Sender Verification to On.
5. Reject SPF Failures
  Turn the Reject SPF Failures option to On.
6. Save Configuration
  Save your changes to apply the settings. These steps will significantly reduce spam on the server.
Adjust Tweak Settings:
1. Log in to WHM
  Access the WHM control panel using root login credentials.
2. Access Tweak Settings
  Navigate to Server Configuration and select Tweak Settings.
3. Modify Email Settings:
  1. Set Initial default/catch-all forwarder destination to Fail.
  2. Limit Max hourly emails per domain to 200.
  3. Turn Count mailman deliveries towards a domain’s Max hourly emails to On.
  4. Set The maximum percentage of failed or deferred messages a domain may send per hour to 60%.
4. Save Configuration
  Save your changes to finalize the settings.