How to add additional SMTP ports

Introduction

You may have requirements to add an additional SMTP port for authentication. This port will allow both STARTTLS and plain text authentication.

Procedure

1. Access WHM as the root user.
2. Navigate to "Home / Service Configuration / Service Manager"
3. Locate the entry for "Exim Mail Server (on another port)"
4. Fill in the text box for the port you wish to use and check the box for "Enabled."
5. Scroll to the bottom of the page and select "Save" to commit the changes.

Please note that if the server has a firewall that blocks communication by default, the port you use here will need to be opened before it can be used.