Thanks Len, >rejecting unknown users at the MX with 5xx is the best defense against dict >attacks
But this allows spammers to determine valid accounts. I guess its better than allowing a zillion message in and having to bounce them. It would be cool to somehow automatically block or blacklist an ip after so many 5xx errors.. >What is the recommended practice? >>export your mailbox users to IMGate. and put them in file that is used by >>check_recipient_maps, which restriction you place at top of your list of >>smtpd restrictions. I'm not using postfix as a gateway, maildirs are my final destination :-) I just tried using unknown_local_recipient_reject_code = 550 but I'm still seeing 450s? -Tony
