Re: [Exim] Unroutable Mail Domain Problem/Possible DNS issue…

Hi Dave,

This is happening with a number of different domains not just one single
domain. In the exim FAQ it suggests that this could be either the DNS
servers are out of step with each other or your DNS library is out of date.
As far as I know both of these are uptodate (although not sure what is the
prefered way to check these). I have also made sure that the root hints are
uptodate as well and they are.

Some of the mailservers this is happening to just have a single mail server
and others have multiple servers. It is what appears to be completely random
except for I have only noticed this happening to Domains that are used
rarely suggesting that it is a problem with the DNS updating somewhere along
the line although I am fairly convinced this may just be down to the network
load on the line and that the DNS queries are just taking their time because
the amount of other traffic on the line. Is it possible that Exim will class
a domain as unroutable if a DNS query takes too long to be returned?

Also is it possible to make exim retry DNS queries on domain lookups either
if it believes that it is unrouteable before bouncing the e-mail back to the
sender?

I have performed lookups using dig on some of the domains that have caused a
problem in the past and these have all been returned successfully without
any problems with all information that should be needed to route e-mail to
the domain. Although some did take a while to return.

Regards,

Justin

----- Original Message -----
From: "Dave C." <djc@???>
To: "Justin Bloom" <justin.bloom@???>
Cc: <exim-users@???>
Sent: Tuesday, May 07, 2002 5:13 PM
Subject: Re: [Exim] Unroutable Mail Domain Problem/Possible DNS issue?


>
> Its also possible, presuming there are two DNS service for the
> domain in question, that one of them is broken/unresponsive, and the
> other is not. 'dig' is your friend in tracking the problem down..