[Mimedefang] Need advise on how to proceed.

[Chris Myers]

----- Original Message ----- 
From: "Brian McGraw" <bjm25 at drexel.edu>
To: <mimedefang at lists.roaringpenguin.com>
Sent: Monday, June 14, 2004 12:45 PM
Subject: Re: [Mimedefang] Need advise on how to proceed.


> >Yesterday we had such an attack. 32000 connects from ~ 1000 hosts in the
> >net, sending each one mail with 32 recipient. Imagine what happens if you
> >accept all the mails and you send bounces ... Bye bye server ...
>
> This is pretty much we where are.  I'd love to implement greylisting,
> but it is sort of a hard sell to management.  People have come to think
> of email as being instantaneous,  even though we all know it is not
> meant to be.  However,  we may be reaching the point where there is no
> choice, as traffic from the bounces is killing our server.

Greylisting only delays mail the first time you see a sender/recipient pair,
all subsequent messages from/to that same pair are accepted immediately.
You can always write your greylisting code so that you don't reject for the
first week or two and THEN turn on tempfails once your database is already
mostly populated.

If you get mail from different people most of the time, greylisting will
slow things down.  If you get mail from substantially the same group of
people all the time, it's *perfect*.

Chris Myers
Networks By Design