Postfix - prevent certain domains from sending to your server

Add the following line in /etc/postfix/main.cf

• smtpd_sender_restrictions = hash:/etc/postfix/access

then modify the access text file in /etc/postfix/ to include the list of rejected senders (similar to below)

• aol.com     REJECT

Then open a terminal window and ‘re-hash’ the access file with the following command

• postmap hash:/etc/postfix/access

Now restart Postfix