[imp] Re: spamassassin and blocking lists

[Iain Pople]

Michael M Slusarz wrote:
> Quoting Iain Pople <ip at brunny.com>:
> 
>> Michael M Slusarz wrote:
>>
>>>
>>> Search the archives for a discussion of this previously.  

i've searched but can't find much. any links would be useful.

> 
> Because you are not thinking of the problem in the correct way.  Received
> headers are added at *every* server stop along the way. Thunderbird 
> delivers as
> follows:
> Thunderbird client --> Mail server
> One hop -- one header.
> 
> IMP delivers as follows:
> Web browser --> Web server --> Mail server
> Two hops -- two headers.  This is our behavior.
> 

I don't think the number of hops (and headers) is particularly 
important. The issue is that a header inserted from IMP triggers 
spamassassin whereas a header inserted by the mail server doesn't.

E.g. The following header triggers spamassassin:

Received: from CPE-203-45-11-59.vic.bigpond.net.au 
(CPE-203-45-11-59.vic.bigpond.net.au [203.45.11.59])
     by webmail.brunny.com (IMP) with HTTP
     for <iain at localhost>; Sun, 24 Oct 2004 10:21:07 +1000

This one doesn't:

Received: from cpe-203-45-11-59.vic.bigpond.net.au ([203.45.11.59]) by 
bwmam09.bigpond.com(MAM REL_3_4_2a 138/139363271) with SMTP id 
139363271; Sun, 31 Oct 2004 14:35:01 +1000

Note, the sending IP address is the same in both cases.

I agree that the bug is most likely with spamassassin, but i'd like to 
know why.

cheers, iain.