On Sun, Jan 30, 2022 at 03:33:16PM +0100, Christoph Pleger wrote:
> > You're mistaken. On input, Postfix provides no LMTP server, and no
> > support for receiving messages from external programs via unix-domain
> > sockets.
>
> I have the following line in master.cf:
>
> usmtp unix n - - - - smtpd
I forgot about that. In this case smtpd(8) pretends it got a connection
from "localhost" and proceeds accordingly. Runnin smtpd(8) in this way
may not be officially supported.
A program with sufficient privileges to access /var/spool/postfix/public
(restricted to the $mail_owner user and/or $setgid_group group) can
inject messages via that UNIX-domain socket, and you can even specify
some other directory via e.g.
../ext/usmtp unix ...
after:
mkdir -m 0755 /var/spool/postfix/ext/
But if you're specifically looking to limit access to privileged (or
internal to Postfix) clients, then "public" may be a reasonable choice.
--
Viktor.
