I have an Ubuntu 16.04 machine with Postfix 3.1.0 and virtual mailboxes (iredmail).
I'm using postscreen (with a local Bind server), Amavis with ClamAV and SpamAssassin.
The amount of received spam is pretty low. The problem is, that the server seems to forward emails which are actual calssified as spam.
For example I have a mailbox on my server foo@mydomain.com. This mailbox has a forwarding to bar@otherdomain.com (the emails are kept in the mailbox). Spam filtereing works pretty well for the messages delivered to foo@mydomain.com on my server. In contrast the mailbox bar@otherdomain.com gets the messages plus all the spam.
I'm using Amavis with smtpd_proxy_filter, hence emails are only accepted if they are not considered spam, all other emails are rejected.
smtp inet n - y - 1 postscreen
smtpd pass - - y - - smtpd -o smtpd_proxy_filter=127.0.0.1:10024 -o content_filter=
My guess is to append the smptd_porxy_filter to the relay service in /etc/postfix/master.cf
relay unix - - n - - smtp -o smtpd_proxy_filter=127.0.0.1:10024 -o content_filter=
I didn't find anything usefull about this topic. Can anyone help me with that?
