Hi everybody! I use ISPConfig 2.2.5 since this Spring 06 and I'm very happy with it! Presently, I have a domain mydomain.tld this morning with a big mail attack tagging Spam but with 100 emails spams by minute just for this domain, it's very dangerous and slow my system for the others domains. For example in maillog: Oct 30 04:53:36 ns0002 postfix/smtpd: NOQUEUE: reject: RCPT from unknown[22.214.171.124] 550 <firstname.lastname@example.org>: Recipient address rejected: User unknown in local recipient table; At this case, the email doesn't pass. But for the others if the user account exists on this domain, the same IP (or other one) will pass... Yeurk! I have see that this attack has an IP with an "unknown" tag. Well I want to know how can I block the "unknown" one on Postfix... I have followed the procedures on Fedora Core 5 x64 for ISPConfig. The version of Postfix is 2.2.8.