How to Enable Greylisting from WHM

Greylisting is an effective and widely applied method that has been implemented in all email servers to reject unknown senders at certain moments. This method relies upon the fact that the sender’s email server will retransmit a message that the recipient’s server rejected, while the latter does not do it most of the time, especially if it is a spam server.

Greylisting reduces the amount of spam emails that reach your inbox by temporarily blocking the sender's IP address and allowing only legitimate sender information to flow through. It is simple to set in the server using the WHM.

Here’s a step-by-step guide on how to enable greylisting in WHM.

Understanding Greylisting

This system works by having the recipients ‘grey-list’ the senders and reply to them by temporarily rejecting their emails and accepting them after some time. The authentic mail servers iwll attempt to deliver the email after some interval has elapsed, but an illicit mail server is less likely to do that and hence reduce spam. 

On the other hand, once a sender name has formed the list successfully with a “whitelisted” tag after a retry, then the subsequent emails from the former are admitted immediately.

Step-by-Step Guide to Enable Greylisting

Step 1: Log in to WHM

- Open your web browser and navigate to your WHM login page. This is usually accessed via https://yourserverip:2087 or https://yourdomain.com/whm.

- Enter your WHM username and password.

- Click "Login" to access the WHM dashboard.

Step 2: Access Exim Configuration Manager

- In the WHM dashboard, locate and click on "Service Configuration".

- Under "Service Configuration", find and click on "Exim Configuration Manager".

Step 3: Configure Greylisting

- In the Exim Configuration Manager, find the section labeled "Basic Editor".

- Scroll down to locate the "Greylisting" section. It may be under the "ACL Options" or a similar heading.

- Check the box or toggle the option to "Enable Greylisting".

- Set the Greylist deferral period. This is the time period during which emails from unknown senders will be temporarily rejected. A typical deferral period is 5 minutes, but you can adjust this based on your preferences.

- Configure other settings such as whitelist exemptions if needed.

Step 4: Save Configuration

- After enabling Greylisting and configuring your preferences, scroll to the bottom of the page.

- Click on the "Save" or "Save Configuration" button to apply the changes.

Step 5: Verify Greylisting is Working

- Send a test email from an external email address to an account hosted on your server.

- Monitor the email logs in WHM or check the email inbox to ensure the email was successfully received after the retry delay.

- Adjust settings if necessary based on the effectiveness and performance observed.

Best Practices for Greylisting

- Monitor Effectiveness: Regularly check your email logs and inbox to ensure legitimate emails are not being unduly delayed.

- Whitelist Trusted Senders: Consider adding trusted senders or domains to a whitelist to bypass greylisting for them.

- Adjust Deferral Period: Fine-tune the deferral period based on the typical retry behavior of legitimate senders.

Conclusion

Disabling greylisting from WHM can also be used as a successful anti-spam measure and improve the protection of emails on your server. Greylisting works by temporarily suspending and requesting senders who are unrecognized to try again. This method of screening effectively eliminates spam while at the same time permitting good mail to pass through the barrier without any considerable delays.

If you need additional help or want to take it to the next level, refer to the documentation or your website hosting master. Reading through this article, it is clear that greylisting is but one of the many solutions that can be used to improve the security and reliability of emails in WHM. When incorporated into your organizational structure, greylisting would improve the smooth running of your email management system.