Hi everyone,
I’m running a fresh iRedMail installation on Ubuntu 24.04 with Postfix as the MTA. I want to automatically reject incoming emails from certain domains (e.g., spammy domains) before they reach the mailbox, rather than just filtering them after delivery. I’ve checked the documentation about Postfix restrictions, but I’m not sure about the best approach in the context of iRedMail’s setup, especially without breaking other functionalities like DKIM or spam filtering.

Has anyone done this successfully? Could you provide an example of the configuration files or steps I should follow to safely block specific domains at the SMTP level?

Thanks!