SA rule that does verify sender

[Ari Jort <ar...@speakeasy.net>]

I've been looking for a SA rule that will do something
comparable to what postfix does with reject_unverified_sender.

The postfix address verification is described here:

http://www.porcupine.org/postfix-mirror/newdoc/ADDRESS_VERIFICATION_README.html

I'd like to use this technique, but would rather assign
a score with SA, rather than make a reject/accept decision 
based on the result.

Has anyone done this already?

Thanks,

ari


-- 
Ari Jort
arijort@speakeasy.net

Re: SA rule that does verify sender

[Ari Jort <ar...@amnh.org>]

Hello,

On Mon, Mar 22, 2004 at 11:23:53PM -0500, Ari Jort wrote:
> I've been looking for a SA rule that will do something
> comparable to what postfix does with reject_unverified_sender.
> 
> The postfix address verification is described here:
> 
> http://www.porcupine.org/postfix-mirror/newdoc/ADDRESS_VERIFICATION_README.html
> 
> I'd like to use this technique, but would rather assign
> a score with SA, rather than make a reject/accept decision 
> based on the result.

I've implemented a verify_sender routine as inspired by 
the postfix address verification, noted above.  Patch
is attached.

This is a naive implementation in many ways.  

1) It assumes the envelope-from is retreivable from the 
Return-Path: header which is true in postfix-land.  I'm not
sure about elsewhere.

2) There's still a bunch of debugging code in here.  I thought
I'd leave it in in this patch, in case it helps anyone else
get it working.

3) It relies on 2 extra perl modules: Net::DNS and Net::SMTP
which might be better outside the spamd process space.  Maybe
a sender verification daemon?

4) It only checks with the highest priority mx record for a given
domain and does not move on to lower priority records.


I'd love some feedback or reports on whether anyone else
can get this working.

Thanks,

ari

-- 
Ari Jort
arijort@amnh.org