Postfix How do I block a domain name in postfix? January 2, 2025 / January 2, 2025 by Philip Newman | Leave a Comment To block a domain name in Postfix, you can use the sender_access feature to reject emails from specific domains. Here’s a step-by-step guide: 1. Edit Postfix Configuration Open the main configuration file: Look for the smtpd_sender_restrictions line. If it doesn’t exist, add it, or modify it to include the check_sender_access directive: The permit ensures valid […] Read more » Postfix