On 10 May 2015, at 13:45, SH Development wrote:
Here is the postconf -n output:
[...]
mynetworks = 127.0.0.0/8
This means that the only network-based trust you have is for the local machine itself. That's often adequate, but it means that you can't permit mail from your separate spam filtering machine via permit_mynetworks.
smtpd_recipient_restrictions = permit_mynetworks permit_sasl_authenticated reject_unauth_destination
There's your problem. "reject_unauth_destination" means you only reject mail if it is not to addresses in local, virtual, and relayed domains. Simply put: as long as the mail is to one of your addresses, you accept it.
Any solution within Postfix requires you to change "reject_unauth_destination" to "reject" and pick a way to permit mail from your spam filter. Simplest: add the IP(s) of the spam filter to mynetworks. You could also make the filtering server authenticate, but that may be complicated. Also, your *best* solution is still to split off authenticated submission to a distinct bonafide port 587 submission service and turn off authentication on your main SMTP inbound service.
Also: Since your documentation directories include '2.6.6' I'm guessing that's your Postfix version and that you are using such an antique because your distribution includes it. Sticking with the standard obsolete version of Postfix in a distribution makes sense if all it is going to do is handle messages from cron jobs and mail/mailx command lines, but it's really not safe for a machine that accepts port 25 connections from random places. If you can't wall this machine off from the world at large because you have users doing submission fom random places, you should at least upgrade to a version of Postfix that has been maintained recently.
