I use an ISP Config Postfix mail server. How do a block a specific spammer's e-mail address or domain to not be able to send mails through this server?
I read through forums and tried the following. I've added this line in the main.cf file:
smtpd_sender_restrictions = check_sender_access hash:/etc/postfix/rbl_blacklist
And I've added the following line in the rbl_blacklist file:
This domain can still send mail / spam through my server.