This is a known bug in the Microsoft SMTP server (the thing that comes with
the NT Option Pack). It correctly interprets temporary errors as temporary
and retries the message, but unfortunately it tries again IMMEDIATELY, which
causes a lot of useless traffic.
I can't advise as to what the problem is with that particular message; I've
seen the problem pop up with various temporary errors, but it's always MS
SMTP on the other end.
The solution is to tell the remote to get a real mail server - this is
pretty broken behavior. You can also, if you have the tarpitting patches
installed, tarpit the remote server, which will at least slow it down until
the remote administrator fixes it.
shag
=====
Judd Bourgeois | CNM Network +1 (805) 520-7170
Software Architect | 1900 Los Angeles Avenue, 2nd Floor
[EMAIL PROTECTED] | Simi Valley, CA 93065
Quidquid latine dictum sit, altum viditur.
----- Original Message -----
From: Michael Boyiazis <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Thu 28 Oct 1999 21.07
Subject: snoop and bare line feeds
> Greetings,
> I occasionally have smtp servers begin to "chatter" with my
> servers and 99% of the time, a telnet to port 25 of the offending server
> yields the dreaded: Microsoft SMTP MAIL
>
> So I block the IP to prevent the chatter as they just keep coming over
> and over again trying to deliver mail which my servers must be saying
> no way to. I ass/u/me that this is a bare-line-feed issue. Since
> everything
> I've read says do the fixcr with "clients" sending buggy mail, my option
> seems to be to block those IP's from sending (tcpserver) and try to get
> mail to them telling them they've been blocked.
>
> I've tried running snoop to see if I could see anything odd with the smtp
> packets, but I really don't know what to look for that is out of the
> ordinary
> so I can tell these folks what to fix. Any suggestions as to what might
> look odd? and what to tell them to fix their mail server?
>
> Thanks,
> mike.
>
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