Re: exim as backup mx

[moseley@hank.org]

On Thu, Oct 23, 2003 at 01:37:27PM +0100, Antony Gelberg wrote:
> Hi all,
> 
> I'd like to set up exim as a backup MX for a friend's domain.  Any tips on
> doing this?  I was going to put the domain in local_domains in exim.conf,
> and have a catchall in /etc/aliases.  But how do I forward the queued
> mail to his server when it comes back up?

I'm glad you asked, because I have been wondering about this, too.


I use "relay_domains" for the secondary, and it's what is suggested at
http://sysadmin.oreilly.com/news/exim_0701.html.  I'm not sure if 
there's a better way.

The problem I find with that is normal checks (like what are valid 
users) are not done.  So when some spammer connects to the main server 
they may get rejected at the rcpt to: line, but on the secondary they 
are not rejected.

I also once set up a "secondary" to be exactly like the primary and 
then used aliases to forward mail to the main.

Unless dealing with a large amount of mail I wonder if it's even worth 
using a secondary.  The only reason for it would be to read your mail if 
you primary machine fails.  For example, for a small home setup if your  
local mail server is down it probably means everything is down, so 
you can't access the secondary anyway.  On my home setup I find that the 
only mail that goes through the secondary is spam.


-- 
Bill Moseley
moseley@hank.org