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Frederick, if you decide you really have to not send NDRs,
then you can follow this KB article:
which tells you where in Exchange to disable sending
NDRs. What it doesn't tell you is that you can create other domains to
which you can still send NDRs, for example, if you have a certain high profile
domains from which you don't get spam.
And just to clarify, this setting in System Manager will
not affect your users; if they send a message to a mis-addressed address, and
the other end sends a NDR, your server will receive it and deliver it to your
user.
In Exchange 5.5, there was a hotfix that enabled a registry
entry to control the behaviour of NDR generation; I don't use 5.5 anymore, but I
know that it exists.
Andrew 8)
Is there not a way to set Exchange to accept them
then trash.
----- Original Message -----
Sent: Monday, February 27, 2006 12:44
PM
Subject: Re: [Declude.JunkMail]
Bouncing emails
You wouldn't. The gateway is not that
smart.
We gave up on attempting to deliver
misspelled emails when we were the subject of a distributed
dictionary attack. No more than ten messages from any IP address, so nothing
could catch it. We got half a million messages a day for months. The
Symantec gateway software was useless in that situation.
Even setting the bounce period to one
day still had the gateway trying to send half a million
bounces.
-d
----- Original Message -----
Sent: Monday, February 27, 2006 12:41
PM
Subject: RE: [Declude.JunkMail]
Bouncing emails
In his setup Symantec would not see the message as a
bounce.
Anyway how would you determine a bounce form a dictionary attack as
opposed to someone who just typed the email address
incorrectly.
Kevin Bilbee
That is exactly why I stopped
using Symantec as a gateway. I tried to get them to add a "don't send
bounces" checkbox or at least a registry entry. but they refused, saying
the Internet RFC's made NDRs mandatory.
-d
----- Original Message -----
Sent: Monday, February 27, 2006
11:50 AM
Subject: [Declude.JunkMail]
Bouncing emails
I am running a filter system listed
below:
1. Front End. Symantec SMTP Gateway.
(Scan Virus and a bit of spam and extensions). Removed 80% of my
problems.
2. IMAIL 8.x and Declude 2.x scan and
forward service.
3. Last Stop. MS Exchange
The problem is when we get a dictionary
attack the exchange server sends a bounce. 550 user
unknown.
The 550's works there way back
through the system and now the SMTP Gateway server attempts to deliver
the bounce for a day.
Anyone know a way of preventing the
bounce.
Thanks.
Fred
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