Re: How to have Exim send to another Exim server before bouncing?

[Paul Mackinney <paul@mackinney.net>]

Ian Melnick declaimed:
> Hello all,
> 
> I'm trying to get mailman working right. We have separate machines for
> web and email, and in order to use mailman's web management tools, it
> needs to be installed on the web server. Don't have the option of
> putting a webserver on the email machine - long story. Anyway, all email
> sent to the domain is put to the email machine, except the email machine
> bounces mail sent to any mailing list because mailman isn't set up on
> that machine!
> 
> I do have exim configured to work properly with mailman on the web
> server, according to the directions on exim.org.
> 
> How can I configure exim on the email machine to try forwarding any mail
> that the transporters couldn't deliver locally to the machine with
> mailman installed? 
This isn't what you want to do. If you did, all email sent from your
domain to other domains would go to/through the web server.

>I'm assuming if mail bounced once it reached the
> mailman machine/web server, it'd bounce back to the email machine and
> bounce again back to the original person who sent it, right?
If it doesn't reach an account that accepts it, it bounces.

> What do I put in the transport config section to have the regular email
> machine try forwarding to the other machine before giving up?
It doesn't work that way. Mail is either forwarded or not. You can route
based on the message headers, body, etc., but not on on whether the
first delivery attempt succeeds.


The solution is to create a dns entry for the web server called
'lists', so that all of your mailman lists have addresses like 

     somelist@lists.yourdomain.com

Now your main email server is entirely out of the loop for all mailman
traffic. The only exim configuration work (other than the mailman
modifications) is to make sure that the list server accepts mail
addressed to 'lists.yourdomain.com' as local mail. This should be easy,
done right at the top of the exim.conf file with a declaration like

    local_domains = localhost:lists

HTH, Paul
-- 
Paul Mackinney
paul@mackinney.net