> On Apr 17, 2019, at 12:46 PM, Noel Jones <njo...@megan.vbhcs.org> wrote:
>
> So basically you want to selectively discard mail during external delivery.
>
> Postfix can't do that by itself. When postfix is delivering mail, it's too
> late to discard it.
>
> You could do this with multiple postfix instances. You'll probably need
> three postfix instances; one for incoming mail, one for local delivery, and
> one for outgoing mail. The outgoing mail instance can then decide what to
> discard as it enters.
> http://www.postfix.org/MULTI_INSTANCE_README.html
Also, the local delivery agent can discard messages, via procmail(1)
and similar, plugged in via one of:
http://www.postfix.org/postconf.5.html#forward_path
http://www.postfix.org/postconf.5.html#mailbox_command
http://www.postfix.org/postconf.5.html#mailbox_command_maps
And of course local delivery via LMTP allows the LMTP server to
discard the message for some or all recipients, possibly based
on Sieve rules.
In both cases the discard mechanism is outside Postfix, in the
downstream software that's processing the message for delivery.
--
Viktor.
