How to change the Exim SMTP port from 25

Introduction

Some network providers block outbound traffic on TCP port 25, preventing users from connecting to the default SMTP port. This article provides the steps to add an additional SMTP port for Exim to listen on.

Changing the port for Exim to something other than 25 will prevent your server from receiving any mail.

Procedure

1. Log into WHM as the ‘root’ user.
2. Navigate to "Home / Service Configuration / Service Manager."
3. Scroll down to "Exim Mail Server (on another port)."
4. Place a checkmark in the "Enabled" and "Monitor" checkboxes.
5. Enter the additional port in the "Allow exim to listen on a port other than 25, 465, and 587." textbox.
6. Scroll down to the bottom of the page.
7. Click the "Save" button.