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From: Pandu Poluan <pandu@poluan.info>
To: gentoo-user@lists.gentoo.org
Subject: Re: [gentoo-user] clamav and spamassassin
Date: Sun, 4 Dec 2011 15:27:57 +0700	[thread overview]
Message-ID: <CAA2qdGVwKrrB-XqBDKnY_HxTXzHPJ4yMveFkkZNKZTJG-eUP=A@mail.gmail.com> (raw)
In-Reply-To: <4EDAE3B1.8050808@orlitzky.com>

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On Dec 4, 2011 10:10 AM, "Michael Orlitzky" <michael@orlitzky.com> wrote:
>
> On 12/03/2011 09:48 PM, Pandu Poluan wrote:
>>
>>
>>
>> Thanks! Very helpful resources.
>>
>> You mentioned amavisd-new. What's their relationship? I mean, if I
>> deploy postscreen, how will it affect amavisd-new?
>>
>
> Postscreen sits in front of smtpd, and handles all incoming connections.
It hands the "good" connections off to the real smtpd daemon. Amavisd-new
(in both before/after-queue configurations) interacts with the real smtpd,
so postscreen doesn't directly affect it at all.
>
> What was I talking about?
>
> With amavisd-new, a before-queue filter is generally nicer, because you
can reject spam, notifying the sender, rather than discarding it or
backscattering. But, amavisd-new is a hog, and with a before-queue filter,
an amavis process gets used every time ANY connection is made. Since 95% of
your connections will be crap (that is a technical term), you waste tons of
resources creating/killing amavisd-new processes for botnets and other scum
that will be rejected quickly.
>
> On a busy server, it will kill you.
>
> Postscreen only passes the "good" connections to a real smtpd, so with
postscreen running, new amavis processes only get used for those good
connections. If postscreen can get reject 90% of the incoming connections,
you'll use an order of magnitude less resources doing before-queue
filtering than you would without postscreen.
>
> So, in essence, postscreen is what allows you to run the before-queue
filter with comparable resources to the after-queue filter.
>

Thanks for all the information. You really should write a wiki.g.o article
about the new setup :-)

Rgds,

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  reply	other threads:[~2011-12-04  8:30 UTC|newest]

Thread overview: 37+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-12-03 19:52 [gentoo-user] clamav and spamassassin Grant
2011-12-03 22:54 ` Michael Orlitzky
2011-12-04  0:59   ` Grant
2011-12-04  1:35     ` Michael Orlitzky
2011-12-04  1:57       ` Grant
2011-12-04  2:10         ` Michael Orlitzky
2011-12-04  1:59   ` Pandu Poluan
2011-12-04  2:17     ` Michael Orlitzky
2011-12-04  2:48       ` Pandu Poluan
2011-12-04  3:06         ` Michael Orlitzky
2011-12-04  8:27           ` Pandu Poluan [this message]
2011-12-06  0:15       ` Grant
2011-12-06  0:45         ` Pandu Poluan
2011-12-06  0:52           ` Michael Orlitzky
2011-12-06  1:01             ` Pandu Poluan
2011-12-06  1:14               ` Michael Orlitzky
2011-12-06  3:24             ` Grant
2011-12-06  4:43               ` Michael Orlitzky
2011-12-06 16:32                 ` Grant
2011-12-06 17:11                   ` Michael Orlitzky
2011-12-06 19:17                     ` Paul Hartman
2011-12-07  0:16                       ` Pandu Poluan
2011-12-06 21:34                     ` Grant
2011-12-06 22:20                       ` Michael Orlitzky
2011-12-07  1:02                         ` Grant
2011-12-07 16:38                           ` Michael Orlitzky
2011-12-07 18:16                             ` Grant
2011-12-07 18:56                               ` Michael Orlitzky
2011-12-07 19:00                                 ` Michael Orlitzky
2011-12-08  0:49                                 ` Grant
2011-12-07  9:15                         ` Pandu Poluan
2011-12-07 16:01                           ` Grant
2011-12-07 16:47                             ` Pandu Poluan
2011-12-07  0:57                     ` Grant
2011-12-07  1:11                       ` Pandu Poluan
2011-12-07 16:34                       ` Michael Orlitzky
2011-12-07 18:08                         ` Grant

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