Re: [exim] accepting failed lookups with "hosts = < host lis…

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Autor: Bill Moseley
Datum:  
To: Exim-users
CC: 
Betreff: Re: [exim] accepting failed lookups with "hosts = < host list >"
Let me try again and be less verbose:

Is there a way to have hosts = with a lookup file ignore
failed lookups until the entire list is processed?

From my tests it seems like if a domain fails to lookup then the test
fails even if a later name in the host list does lookup and then
matches the ip of the connecting machine.




Second question is off topic, but from your reading of the RFCs is
a valid envelope sender is required?

The mail in question was:

    mail from: <invalid local>@<valid domain>


    From: <invalid local>@<valid domain>
    To: <real sender's addres>
    Reply-To: <real sender's address>






On Mon, Apr 03, 2006 at 09:56:37AM -0700, Bill Moseley wrote:
> I'm using an accept hosts file lookup for use in white-listing some
> hosts.
>
>   accept hosts = ${if exists{CONFDIR/local_host_whitelist}\
>                         {CONFDIR/local_host_whitelist}\
>                         {}}

>
> I realize IP addresses are better, but if I have a list of domain
> names in that file and one of them fails to lookup then processing
> stops and the accept fails. That is if my list looks like:
>
>     invalid_domain.com
>     exim.org

>
> Then when exim.org connects it is not accepted because invalid_domain.com
> didn't lookup and processing of the list stopped.
>
> Is it possible to ignore the failed dns lookups until the *entire* list
> is processed? In the example above, ignore that invalid_domain.com
> failed to lookup and then test for a match on exim.org?
>
>
>
> BTW -- this came up due to a problem with sender verify. I know it's
> a debatable practice. I've been using it for a year or two on a few
> small domains and it's been a huge help.
>
> But, about once or twice a year I have a host that send out legitimate
> mail with invalid envelope sender addresses (once that can't be sent
> mail) and I need to white list them.
>
> I'm not clear from my scan of rfc2821, but are senders required to
> use valid envelope sender addresses? If they really don't want
> bounces back would a null sender be more appropriate than using an
> invalid address?
>
>
> The latest one sends mail on behalf of others. They send an invalid
> local part of the envelope sender. They use that same address in
> their From: header. Then they place a valid address in the Reply-To:
> header (which also matches the To: header).
>
> They claim the mail is fine because the envelope sender includes a
> valid domain name and also that they include a valid Reply-To:
> header. My spam filters don't agree. ;)
>
>
>
>
> --
> Bill Moseley
> moseley@???
>
>
> --
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>


--
Bill Moseley
moseley@???