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Configuring a Smarthost Using Imunify Email for Advanced Filtering

Written by Mehmet Suslu | Mar 13, 2025 10:45:00 AM

Imunify Email is an advanced email filtration solution that integrates seamlessly with cPanel's Exim mail server. Functioning as a pre-routing configuration, it intercepts emails before other routing configurations are applied.

After interception, Imunify Email forwards the messages to its powerful antispam engine for detailed filtering and analysis. If the email is deemed legitimate and free from spam or malicious content, it is returned to Exim for standard processing and delivery.

 

Mail Flow with Imunify Email

What Is a Smarthost?

A smarthost is a type of email relay server designed to route outgoing email messages from a local server to the recipient’s mail server. By acting as an intermediary, it ensures secure and efficient email delivery. In an Exim configuration, a smarthost is configured as the final router, which allows additional tasks, such as email filtering by tools like Imunify Email, to be carried out effectively.

 

Mail Flow with Imunify Email and Smarthost

 

Configuring a Smarthost with Imunify Email and cPanel Exim

Since Imunify Email operates as a pre-router within cPanel's Exim mail server, it re-injects emails determined to be safe back into the Exim queue. From there, Exim processes these emails as usual without further involvement from Imunify Email. This design supports a standard smarthost configuration for Exim, detailed below:

 

Through the cPanel WHM Smarthost Configuration

1. In WHM, navigate to:
Service Configuration » Exim Configuration Manager » Basic Editor.

(see the official documentation)

2. Under the "Mail" tab, set the Smarthost support value to:
* <smarthostip>
Replace <smarthostip> with the server IP address provided by your smarthost service provider.
3. Click the Save button.

 

Through the Special Router Configuration

For advanced control, you can configure a smarthost using:
Service Configuration » Exim Configuration Manager » Advanced Editor.
Follow the step-by-step instructions on the official documentation page for additional details.

 

Maximizing Efficiency and Reducing Costs with Imunify Email

If your current email filtration system relies on a smarthost, integrating Imunify Email offers substantial benefits:

  • Reduces Network Usage: Imunify Email acts as a pre-router, filtering spam and malicious messages before they reach your smarthost.
  • Decreases Costs: By blocking spam at the source, fewer messages are sent for processing, reducing network traffic and potentially lowering expenses—especially when using third-party managed smarthosts that charge per message.
  • Enhances Security: Filtering spam at the initial stage improves email security, offering a more efficient and secure operational workflow.

With Imunify Email, you can improve your email system’s efficiency, security, and cost-effectiveness by filtering spam at the source and optimizing the delivery process.