Problem #

Your WHMCS installation is not sending email or the sent email doesn’t display properly. When you check the log at Configuration () > System Logs, you see the following error:

Smarty Error: Not allowed by security policy

Cause #

The email template contains advanced code that the default email security policy blocks.

Solution #

To resolve this issue:

1. Review the code in the email to confirm what it’s trying to send at Configuration () > System Settings > Email Templates.
2. Add an exception to the email security policy to allow the desired code.

Last modified: 2025 July 28