Solved

Exchange 2007 - Failure DSNs Total

Posted on 2013-01-14
15
1,767 Views
Last Modified: 2013-03-09
Hello,

I observed that in my Hub transport server (exchange 2007)the Failure DSNs Total  valuse is more than 32000. Is that normal or any issues?

I didnot see any error in events.

If it is the issue please some one help to decrease this value.
0
Comment
Question by:Haribaskaran
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 6
  • 6
  • 2
15 Comments
 
LVL 37

Expert Comment

by:ArneLovius
ID: 38778484
Without knowing the content of the Delivery Status Notification messages, but presuming that they are "failures" it is difficult to know the cause

Are they for internal or external addresses ?

Is your server running as an open relay ?

Are you filtering inbound email against valid email addresses ?
0
 
LVL 52

Expert Comment

by:Manpreet SIngh Khatra
ID: 38779051
Just to add to Arne

Perfect point of Open relay ....
Check with EXBPA if that reports any errors ..
How many servers and hope you have AV and ensured no server is affected ?

- Rancy
0
 

Author Comment

by:Haribaskaran
ID: 38779117
Hello ArneLovius,

It is not opened relay we are relaying the mails via forefront solutions.
0
Online Training Solution

Drastically shorten your training time with WalkMe's advanced online training solution that Guides your trainees to action. Forget about retraining and skyrocket knowledge retention rates.

 
LVL 37

Expert Comment

by:ArneLovius
ID: 38779185
the other three questions in my post are also relevant

as per Rancy, running the ExBPA is an excellent suggestion.

Running ForeFront would make is harder to be an open relay, but certainly not impossible...
0
 

Author Comment

by:Haribaskaran
ID: 38779213
Ok Let me  run the EXBPA and share the result.
0
 

Author Comment

by:Haribaskaran
ID: 38779623
Hi I ran the EXBPA and I didn't see any errors reated to this. I have attached the screen shot of that.
Test.jpg
0
 
LVL 37

Expert Comment

by:ArneLovius
ID: 38779743
Are they for internal or external addresses ?

Are you filtering inbound email against valid email addresses ?
0
 

Author Comment

by:Haribaskaran
ID: 38779900
That is for External. yes Inbound mail filtering enabled against valid email addresses.
0
 
LVL 37

Expert Comment

by:ArneLovius
ID: 38779980
in which case, time to do some research.

open the most recent DSN and note down who it is To:
now use the tracking log to see if you can find the original.
If you can find the original, this will tell you who it was To:

I'm going to guess that either the mail filter for valid addresses is not working, or that your outbound gateway is not allowing you to send DSN messages.
0
 

Author Comment

by:Haribaskaran
ID: 38780021
OK Let me check on that.
0
 
LVL 52

Expert Comment

by:Manpreet SIngh Khatra
ID: 38781485
Arne i guess we should place Recipient and Sender Filtering as well ?

- Rancy
0
 
LVL 37

Accepted Solution

by:
ArneLovius earned 500 total points
ID: 38782047
I always enable recipient filtering on the mail gateway, whether this is n Exchange HT role, Edge Transport or 3rd party mail gateway, this is to ensure that DSN failure emails are NOT sent for invalid email addresses, DSN failures should be sent by the sending mail server back to the sender.

If recipient filtering is not enabled it can lead to a build up of DSN failure messages as described, these can also be used in an "amplification attacks" where a zero sized email from a spoofed address turns into a DSN failure to the attacked address.

I only use sender filtering to block known "spam" or "harassment" email addresses.
0
 

Author Comment

by:Haribaskaran
ID: 38842390
I resolved this issue, thanks for all response.
0
 
LVL 37

Expert Comment

by:ArneLovius
ID: 38843007
how did you resolve it ?
0

Featured Post

Has Powershell sent you back into the Stone Age?

If managing Active Directory using Windows Powershell® is making you feel like you stepped back in time, you are not alone.  For nearly 20 years, AD admins around the world have used one tool for day-to-day AD management: Hyena. Discover why.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Following basic email etiquette rules will help you write a professional email and achieve a good, lasting impression with your contacts.
It’s been over a month into 2017, and there is already a sophisticated Gmail phishing email making it rounds. New techniques and tactics, have given hackers a way to authentically impersonate your contacts.How it Works The attack works by targeti…
The basic steps you have just learned will be implemented in this video. The basic steps are shown to configure an Exchange DAG in a live working Exchange Server Environment and manage the same (Exchange Server 2010 Software is used in a Windows Ser…
Windows 8 came with a dramatically different user interface known as Metro. Notably missing from that interface was a Start button and Start Menu. Microsoft responded to negative user feedback of the Metro interface, bringing back the Start button a…

734 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question