How to restrict access to SMTP

Introduction

Some administrators want to restrict SMTP access on their servers from specific IP addresses. This article provides the procedure for blocking access to SMTP for individual IP addresses or address ranges.

Procedure

1. Log into WHM as the ‘root’ user.
2. Navigate to "Home / Service Configuration / Exim Configuration Manager."
3. In the "Basic Editor," click the "Access Lists" tab.
4. Click the "Edit" button on the "Blacklisted SMTP IP addresses" line. 
5. Enter the IP address or IP range to block in the "Spammers and Abusers (Black List)" textbox.
   Please note that each additional address or range must be entered on a new line.
6. Click the "Save" button to save the changes to the list.
7. Scroll to the bottom of the page.
8. Click the "Save" button to update and apply the new configuration.

Additional resources

Exim Configuration Manager Basic Editor: Access Lists