As is typical, I found the actual problem just after posting the query.
Running 'exim -bh <a-local-ip>' revealed that one of the files we check
against as part of our anti-spam processing, which should have contained
only IP addresses, actually had some random other data at the end of it.
This file is built by grepping the logs for Spamhaus rejects and then
auto-blocking (before the Spamhaus lookup) any hosts we already know have
been blocked that day - the idea being to reduce the load on the Spamhaus
DNS infrastructure. We have a commercial Spamhaus account but I still
believe in being a good netizen and not loading things unnecessarily - we
get very thick spammers who will carry on hammering away despite getting a
500-rejected-due-to-spamming response to every message. Up till now this
has worked perfectly but today something went wrong and the grep pulled out
some random text at the end of the process.
I've now modified the scripting that builds the check files to double-check
that only correctly formed IPs are listed, which resolved the problem.
So I'd thoroughly recommend exim -bh <ip-that-is-allowed-to-relay> as a
good way to debug seemingly bizarre Exim issues.
Thanks for reading!
On 20 March 2014 17:22, Jeremy Harris <jgh@???> wrote:
> On 20/03/14 17:11, Pyromancer wrote:
>
>> search_tidyup called
>>
>
> That gets called from many places. Can you give the debug output leading
> up to that?
> --
> Cheers,
> Jeremy
>
>
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