Re: [Sqlgrey-users] Using SQLgrey in an ISP environment

[Lionel B. <lio...@bo...>]

Josh Endries wrote the following on 12/15/04 07:40 :

> -----BEGIN PGP SIGNED MESSAGE-----
> Hash: SHA1
>
> Lionel Bouton wrote:
> | I didn't realise you could make Postfix use the greylisting policy
> | daemon after alias expansion. How do you do that ?
>
> Well, I lied (kinda). I do it via multiple instances (actually,
> multiple physical servers).
>

I'm not sure I see how you do it. Here's what I imagine (probably 
because this was the process I thought of when trying to) :
- a first pool accepts the messages, processes alias expansion and 
forwards the messages to a second pool
- the second pool greylists.
But it doesn't work : the first pool did already accept the message when 
the second wants to greylist.

I just realised that in fact it shouldn't be possible to do greylisting 
after alias expansion. Let me explain :
- Postfix handles the domain example.com
- there'a an alias "adm...@ex..." expanding to the final 
recipients "pos...@ex..." and "ro...@ex...".
- Postfix wants messages to root being greylisted and not messages to 
postmaster.
- The greylister doesn't know yet that "se...@ot..." on 
123.48.12.58 is a valid couple.
- se...@ot... sends an e-mail from 123.48.12.58 to 
adm...@do...
What should Postfix do ? It can't refuse the mail because postmaster 
doesn't want its incoming messages to be greylisted but at the same time 
root doesn't want to receive messages that haven't been greylisted so it 
can't accept it either.

Conclusion : no greylisting before alias expansion

Lionel.