Re: [exim] Greylist -Hosts sending from Multiple MX's.

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Author: Patrick von der Hagen
Date:  
To: exim-users
Subject: Re: [exim] Greylist -Hosts sending from Multiple MX's.
Grant Peel schrieb:
> Hi all,
>
> A few months back, with alot of help from this list, I implimented
> GREYLISTING (which is working well), with one exception:
>
> Some ISPs (mail hosting farms, Spam scanning services etc, sometimes resend
> from a different MX each retry period, which, obviously, causes some serious
> email delays - todays for example, was delayed about 8 hours.
>
> Question: Is there an expression we can add that will only look at the FQDN
> or change the FQDN (as opposed to the full MX name?

As an alternative suggestion: the messages do come through, so you have
the sender-ips in your database with entries indicating that they passed
greylisting successfully. I consider it to be normal when using
greylisting, to analyse those ips that pass greylisting and to create
whitelists based on that analysis. E.g. an IP that again and again
passes shouldn't be subject to greylisting permanently.
So after some learning period, those ISPs should end on your "do not
greylist"-whitelist and the problem should disappear.

I suppose in your database-setup you need a cronjob to tidy up anyway.
Such an extension shouldn't be to difficult, just something like "select
ip, count(*) from table group by ip;"

--
CU,
Patrick.