Re: [exim] localhost mail loop created by bad IPv6 AAAA DNS …

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Συντάκτης: Dominic Cleal
Ημερομηνία:  
Προς: exim-users
Αντικείμενο: Re: [exim] localhost mail loop created by bad IPv6 AAAA DNS record
On Mon, 21 Aug 2006 11:31:53 -0500
"J. Ryan Earl" <ryan@???> wrote:

> Here we see the problem, the AAAA record for clsmail.com is setup
> incorrectly. The temporary workaround is to stop exim for a minute
> to let the email timeout in looping to itself, however, as soon as an
> autosearch for this user is run again the email loop starts up. Now
> I'm trying to figure out the best permanent workaround. I did some
> research and basic googling on the matter and found:
> http://www.exim.org/exim-html-4.62/doc/html/spec_html/ch13.html#id2569429
>
> disable_ipv6 appears to have been added after Exim version 4.43, so I
> can't use that. Instead I added the following to exim.conf:
>
> # turn off IPv6 lookups
> dns_ipv4_lookup = true
>
> However, that didn't seem to help any, the email loop resurfaces.
> I'm hoping that I won't have to build my own custom installation of
> Exim to fix this problem as this is installed on a heavily used
> production system and a new Exim installation would be a huge
> variable I'd like to avoid. Does anyone know of a permanent
> workaround to disable IPv6 AAAA lookups with the stock RHEL4 version
> of Exim?


Check the ignore_target_hosts option for the transport. It's normally
set to "0.0.0.0 : 127.0.0.0/8" which will stop it delivering to
localhost over IPv4. In the spec, it gives a couple of examples on how
to block all IPv6 deliveries with it:

http://www.exim.org/exim-html-4.60/doc/html/spec.html/ch15.html#id2604632

--
Dominic Cleal
dominic@???