> When your exim isn't listening on port 25, the decision about
> accepting an email or not is taken out of exim's hands.
> When your anti-spam daemon has _accepted_ a mail, rejecting it with
> exim doesn't actually have any effect...
>
It attempts delivery to Exim before the final 250 accepted response, and if
Exim rejects, that rejection is passed back to the sending MTA.


> My exim is listening on port 825 for incoming connections. In my
> exim.conf, I added the lines
>
> # Run exim on smtp-backdoor Port:
> daemon_smtp_port = smtp-backdoor
>
> and my /etc/services contains the following entries:
>
> smtp 25/tcp mail
> smtp-backdoor 825/tcp
>
> Thus, exim listens on port 825 for incoming connections, but correctly
delivers
> outgoing mails to remote port 25.
>
> Changing exim's port from 25 became necessary because I'm running an
> AntiVir daemon that "occupies" port 25 and passes scanned mails on to
>
Yes, exactly what I am trying to do, but I couldn't get the exim.conf sorted
out - Exim would not compile.

/* from the docs */
11. Main configuration
The first part of the run time configuration file contains the main
configuration settings.

daemon_smtp_port
Type: string
Default: unset
This option specifies the numerical port number or the service name
equivalent on which the daemon is to listen for incoming SMTP calls. It is
overridden by -oX on the command line. If this option is not set, the
service name `smtp' is used.

There is the problem: WHM adds an -oX option of SSL port 465 every restart
(and it restarts Exim quite a few times a month during its nightly
upgrades). Looks like I will have to go to the WHM list to finish this job.


> Chris, I'm wondering why you obviously tend to a kind of "special
> solutions".
> Just have a look at the docs that are shipped with the exsican-acl
> patch. It mentions examples of how to integrate Anti-Spam-software
> into exim's ACLs. With this setup, you can even scan mails "at SMTP"
> time...

Oh, believe me I read ACL and Exiscan docs and source code until my eyes
hurt. Needed a solution that could port to any MTA in any network
configuration, and Exiscan looked too much like a 'special solution'. An
SMTP daemon seemed the perfect choice. I had already written a perl
pop-forwarding script that did 90% of what I wanted, so integrating it with
assp was a snap.