Re: [Exim] Filtering

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Author: Dennis Taylor
Date:  
To: Exim
New-Topics: wishlist item (was: Re: [Exim] Filtering)
Subject: Re: [Exim] Filtering
A lot of spammers put a tag on their subject line which consists of a
number of spaces and some garbage. I guess they're trying to avoid subject
filters, but it actually tags the mail as spam.

This is what works for me. Catches a lot of crap. The header_to test
ensures that anything actually addressed to someone in our domain gets
through. Very few spammers bother to individually address their crap.

The only danger is if a mailing list that you are on sends you some email
that fits this. If you are concerned about this, you can test for mailing
list sources (i.e. exim.org) earlier in the filter (I can't remember
offhand what the command is to cease filtering and accept the mail).


if $header_to does not contain "pctc" and
   (
   $header_subject matches "
    -[a-z0-9][a-z0-9]*\\$" or
   $header_subject matches "
[a-z0-9][a-z0-9]*\\$" or
   $header_subject matches "
\\\\[[a-z0-9][a-z0-9]*\\\\]\\$" or
   $header_subject matches "
\\\\([a-z0-9][a-z0-9]*\\\\)\\$"
   )
then
        fail text "SPAM is not acceptable at this site"
        finish
endif



At 01:59 PM 9/12/00 -0400, Jason Robertson wrote:
>Thanks Philip was wondering about this in relation to subjects..
>
>Though i do have a few tests that work on catching some spam.. The
>problem I have now is that I need to filter on more items
>
>if ($h_message-id contains <>) then
>if ($h_Message-ID contains <@>) then
>if (("${if !def:header_to: {nospam}}" is nospam ) (this is catches good
>messages too)
>if ($h_to: contains <> ) then
>if ($h_from: begins @) then
>if ($header_subject: is "Search Engine Secrets Discovered" ) then
>
>
>
>
>On 12 Sep 2000, at 10:32, Philip Hazel wrote:
>
>> On Tue, 12 Sep 2000, Scott Stavretis wrote:
>>
>> > How can I run this so that I can jsut put one enty in my main filter

file that
>> > points to another file that just has the addresses in it?
>> >
>> > eg. /etc/filter contains
>> > if $header_from contains "**SOMEHOW POINT TO /etc/filter.addresses **"

then
>> > fail text "INVALID ADDRESS" endif
>> >
>> > and /etc/filter.addresses contains a list of e-mail addresses
>>
>>
>> if ${lookup{$header_from:}lsearch{/some/file}{yes}{no}} is yes then
>>
>>                         ^
>>                         ^
>>                 This colon is important.        

>>
>> -- 
>> Philip Hazel            University of Cambridge Computing Service,
>> ph10@???      Cambridge, England. Phone: +44 1223 334714.

>>
>>
>>
>
>
>
>---
>Jason Robertson                
>Network Analyst            
>jason@???    
>http://www.astroadvice.com      

>
>--
>## List details at http://www.exim.org/mailman/listinfo/exim-users Exim

details at http://www.exim.org/ ##
>

---
Dennis Taylor
---
Don't worry about people stealing your ideas. If your ideas
are any good,
you'll have to ram them down people's throats.