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Re: postfix getting DOSed from rejected mail from other server

From: Alan (alanufies.org)
Date: Wed Apr 28 2004 - 13:06:17 CDT


On Wed, Apr 28, 2004 at 01:55:39PM -0400, Wietse Venema wrote:
> Alan:
> > Howdy folks...
> >
> > Last night I had a user note that my system was quite slow, and after a
> > bit of investigation I found that the 2+ load was caused by postfix. A
> > user had a procmail rule to forward all mail to him to his home domain,
> > hosted on a random hosting companies server (ez123host or something like
> > that). Anyway, they were having some sort of problems with their
> > system which went from 'temporary local problems' to straight out
> > rejecting legitimate mail with 550. Anyway, my postfix was cheerfully
> > trying to send mail to them at the rate of two a second or so, continuously.
> > Just wondering what I can do to throttle this if it happens again.
>
> # find / -name procmail -exec rm -rf '{}' ';'

:) I don't think that's a viable solution somehow....

> The problem is that procmail sets the sender to the address
> of the forwarding user, so that delivery problems multiply.

But even when I used netcat/telnet to try to send mail from the command
line, setting sender and recipient properly it gave the same error (see
the last set of pastes in my previous message.

alan
--
Alan <alanufies.org> - http://arcterex.net
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