Re: MailScanner/Exim

[Craig Sanders <cas@taz.net.au>]

On Sat, Jul 29, 2006 at 01:32:17AM -0400, tps wrote:
> I'm trying to help a buddy set up his mail system a bit better. We
> have exim4 and MailScanner set up on his primary machine and also
> his secondary MX. His primary gladly chunks mail for non-existant
> users. However, anything that gets pushed to his secondary just gets
> forwarded to the primary, and that can be a lot of crap. The two
> systems are virtuallly mirrors, with just the slight config change for
> exim on the secondary.
>
> I can't get my mind around this, although I know there has to be a
> way.  How can I have the secondary validate the recipient and not
> simply forward it to the primary for delivery?

1. extract the valid users list from /etc/passwd, /etc/aliases, and
wherever else they may be.

2. use scp/rsync or whatever to copy them to the MX backup.

3. put them into a lookup file (hashed db or btree or whatever preferably
for speed) for exim on the backup MX.

4. put all of the above into a cron job. or script it so that you can just
run one command to update the backup MX whenever you add/delete/change
users and aliases.

5. configure exim on the backup MX to use that lookup to validate relay
recipient addresses.


postfix has a relay_recipients lookup feature for this. dunno what the
equivalent is in exim (or even if there is one), but there's probably
some way to do it.


craig

-- 
craig sanders <cas@taz.net.au>           (part time cyborg)