Re: [exim] whitelist a domain

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Author: Todd Lyons
Date:  
To: exim-users
Subject: Re: [exim] whitelist a domain
On Wed, Mar 12, 2014 at 5:37 AM, Heiko Schlittermann
<hs@???> wrote:
> basti <basti@???> (Mi 12 Mär 2014 13:19:27 CET):
>> Hello,
>> i have running exim4 (4.80) on debian.
>> All is running fine, now I need to get a mail from google with a
>> response link, the link is only valid for a few minutes an is send from
>> different servers so it is greylist again and again.
> You should redesign your greylisting approach. Greylisting keyed on
> sender ip address is simply wrong. (IMHO)


Agreed, it

> We do greylisting (if at all) keyed on "$sender_address/$local_part@$domain".
> Exactly because some larger domains use different servers for different
> delivery attempts.


We do greylisting per
"$sender_address:$local_part@$domain:$sender_host_address", but only
if the IP doesn't reverse resolve to anything or if its rDNS looks
like a dynamic IP. In general, we find that:
1) any multiple outbound IP system is properly designed and has rDNS,
so it doesn't hurt them.
2) any sending system which does not have rDNS is not sending
something we will want.
3) any sending system which does have rDNS but is a consumer
cablemodem or dsl modem is either a spam source or using
mis/non-configured SMTP Auth.

YMMV, but it works for us.

...Todd
--
The total budget at all receivers for solving senders' problems is $0.
If you want them to accept your mail and manage it the way you want,
send it the way the spec says to. --John Levine