I have an interesting question for you. How would you setup a fail2ban service to send automatic ban notification's if you have blocked the servers SMTP connections on the border gateway firewall? Postfix does not have (and will not have) releayhost defined to ensure no SPAM (or as little SPAM as possible) is sent from the webserver. All the websites have to define proper SMTP authentication server and credentials to send email (but that is another story.) All the email should travel trough the SMTP server using proper authentication. How ever fail2ban does not seem to have separate configuration for SMTP settings. I'm wondering if it is possible to setup SMTP settings (and maybe credentials) for fail2ban?