Re: [exim] IP hearder checking for real time blacklist

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Author: Daniel Tryba
Date:  
To: exim-users
CC: Kebba Foon
Subject: Re: [exim] IP hearder checking for real time blacklist
On Monday 28 November 2011 17:29:17 Kebba Foon wrote:
> Thats not something i have considered, but if i can run spam/virus scan
> on outgoing mails maybe this will reduce this problem. i understand that
> will also cause a lot of load on my servers, but atleast i will not
> receive disturbing mails pointing out how inefficient my system is.


My solution is to have clients route their MTA through an asmtp server which
is running spamassassin to block obvious spam. To avoid this mail getting
blacklisted if their external IP adress gets listed I remove the Received
headers on forwarding in the remote_smtp transport:

remote_smtp:
        driver                  = smtp
        headers_remove          = "Received"


Malware doesn't appear to be smart enough to use a clients MTA, so it tries to
deliver mail directly to targets (which offcourse should be firewalled
anyway). So when they start spamming, their IP gets listed but legitimate mail
still gets through. My amstp server has never been blacklisted sofar.

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