Re: [Exim] New HELO check suite

Top Pagina
Delete this message
Reply to this message
Auteur: Tor Slettnes
Datum:  
Aan: Andrew - Supernews
CC: exim-users
Onderwerp: Re: [Exim] New HELO check suite
On May 25, 2004, at 15:51, Andrew - Supernews wrote:
>
> Tor>  condition = ${if eq {${lookup
> dnsdb{a=$sender_helo_name}{$value}}} \
> Tor>                      {$interface_address} \
> Tor>                      {yes}{no}}

>
> That'll lose you some mail from sites where the HELO name is actually
> a valid FQDN, but isn't resolvable from outside the sender's network
> (I've seen that happen several times for various reasons). In such
> cases
> the "deny" above may end up deferring the mail indefinitely, since the
> dnsdb lookup will cause it to defer on a query timeout or SERVFAIL.


No, that is bad information.
Note that the statement above does NOT read:

    ${if eq {${lookup dnsdb{a=$sender_helo_name}{$value}fail}}} ...
                                                        ^^^^


Without the "fail", if the "dnsdb" lookup fails, an empty string is
extracted. No harm done.

BTW, I know what I am talking about. As you probably could tell, I am
using this condition myself.

-tor