Re: [exim] Backup MX and exim4

> In exim i have in configure a
>
> domainlist relay_to_domains =
> ${lookup{$local_part@$domain}lsearch*@{/usr/exim/relay_domains}}
>
> to do the same. I thounght, that should be solution, but i failed.

As someone else said, I suggest to omit $local_part@ and use lsearch
instead of lsearch*@, because you deal with domains, not addresses.
See section 9.5 and 9.6 of the Exim specification for differences.

I recommend to use

domainlist relay_to_domains = @mx_any

It requires no further configuration and always does what DNS says.
Sure, someone may abuse you as free backup MX, but if so, it is likely
that you will see his mail in your queue when the primary MX is down and
read or remove it. Not exactly what one wants his backup MX to do. :)

In case you meant to match addresses, because your backup MX does
recipient verification, don't use a domain list.

Michael