Procedure:
- Log in to WHM.
- Navigate to the “Service Configuration” section and click on the “Service Manager” option.

- Find the option Exim Mail Server (on another port) and enable it by selecting the corresponding radio button.
- Set the port to 26 or 587 (as recommended), or add any other custom port like 588 if needed.
- Scroll down and click “Save” to apply the changes.
Important: Ensure that the newly added TCP port is opened in both local and external firewalls to allow inbound traffic to the server.
That is it! Do not hesitate to contact our support team for assistance. Also Read: How Can I Check My SMTP Server Address?