On 28/01/2010 15:55, Alain Williams wrote:
> The recent discussion on GreyListing made me think that this is something that
> I should really to: take it out of the box marked ''do later''.
>
> I looked at the various implementations suggested for Exim and did not like
> any of them and so wrote one that is:
>
> * smaller in terms of exim.conf
> * uses an sql procedure - should be faster
>
> I have written it up at the URL below, I have put this up on a test machine and it seems
> to work.
>
> I would be grateful if this was looked at by the collected wisdom of the various readers of this list.
> I have marked it beta, I will make changes if you can see bugs or think that the documentation
> is not good enough.
>
> http://www.phcomp.co.uk/TechTutorial/HOWTOs/GreyListing.php
>
> Notes for discussion:
>
> * It stores sending-domain& IP address of sender.
> If a site sends from many MTAs it will be greylisted many times.
> The alternative would be to record then entire sender address (boo@???),
> however I do see spam that supposedly originates from the machine that it
> is being sent to -- so not a good idea.
Looks good. I would update the function to purge old data from the
database as well though. Something like:
DELETE FROM greylist WHERE last_received < DATE_SUB(NOW(),INTERVAL 100 DAY);
Could use RAND() to make it so that the "purge" is run only once every
100 executions or something. Something like:
IF RAND() < 0.01 THEN
DELETE FROM greylist WHERE last_received < DATE_SUB(NOW(),INTERVAL
100 DAY);
END IF;
--
Mike Cardwell : UK based IT Consultant, Perl developer, Linux admin
Cardwell IT Ltd. : UK Company - http://cardwellit.com/ #06920226
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