Re: [gentoo-user] clamav and spamassassin

[Pandu Poluan]

On Dec 4, 2011 10:10 AM, "Michael Orlitzky" <michael@××××××××.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,