On Mon, Mar 25, 2024 at 04:11:47PM +0100, Daniel Marquez-Klaka via
Postfix-users wrote:
> I have a problem with check_sender_access that I can't find a solution to.
>
> 2 postfix mail server, one, mail-server1, is connected to the
> internet, the second, calling it list-server1, which serves a few
> mailing lists, is only reachable thru mail-server1.
>
> On mail-server1 a transport map entry sends everything for
> @list-dom.de to list-server1, list-server1 does his work and sends all
> back to mail-server1 which then delivers to the final destination.
>
> On list-server1, to prevent the whole world sending mails, I have
> installed a check_sender_access map to accept a few allowed domains,
> reject everything else.
The problem is self-inflicted, the access checks are in the wrong place.
The access(5) checks need to be implemented *at* the edge relay
(server1), not the downstream list server.
> ... bounces, as the are send with empty FROM (<>), as I understand to
> prevent loops, get rejected to. This is a problem because nobody will
> ever notice if there are dead emails in a list. Also, automatic bounce
> handling (I am using mailman3 on list-server1)
> will never do anything.
The vast majority of bounces will happen at the outbound edge relay,
when remote systems reject the outgoing mail. These will not run into
any access check issues, once they're implemented in the right place.
Some bounces will be remote, you can use a milter to process remote
bounces, parsing the bounce multipart/report.
Bottom line, all filters belong on the relay, not the internal server.
--
Viktor.
_______________________________________________
Postfix-users mailing list -- postfix-users@postfix.org
To unsubscribe send an email to postfix-users-le...@postfix.org
