RE: Idea to disappoint Spammers

> [ On Sunday, February 1, 2004 at 14:49:11 (+0100), Rene
> Bartsch wrote: ]
> > Subject: Re: Idea to disappoint Spammers
> >
> > Tar pit - then they'll remove your smtp-server from their lists ...
>
> I wish that worked as you say -- so far it hasn't happened to
> any server I've seen or heard tell of, not in over six years
> of trying.
>
> But it is a low-cost way to delay them while at the same time
> preventing them from throwing their crap at you, especially
> if they know many of your user's addresses, and at the same
> time it prevents various errors, malicious and unintentional,
> from causing further damage.

But isn't the smtp_proxy feature designed for low-traffic sites?

Pros and cons of before-queue content filtering

The before-queue content filter allows Postfix to reject mail before the
incoming SMTP mail transfer completes, so that Postfix does not have to send
rejected mail back to the sender (which is usually forged anyway). Mail that
is not accepted remains the responsibility of the remote SMTP client.

The problem with before-queue content filtering is that the remote SMTP
client expects an SMTP reply within a deadline. As the system load
increases, fewer and fewer CPU cycles remain available to answer within the
deadline, and eventually you either have to stop accepting mail or you have
to stop filtering mail. It is for this reason that the before-queue content
filter can be used only on low-traffic sites.

Another problem is that content filtering software can use lots of memory
resources. In order to not run out of memory you have to reduce the number
of before-filter SMTP server processes so that a burst of mail will not
drive your system into the ground with too many content filter processes.
This, in turn, means that SMTP clients have to wait for a long time before
they receive service.

Peter Santiago peters@psinergybbs.com
My website: www.psinergybbs.com
My spamtrap address: r34987y@psinergybbs.com

!****************************************!
! Black Holes are Out of Sight !
!****************************************!