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MSExchangeTransport 3008 Error only

lindemannfox asked
Medium Priority
Last Modified: 2010-05-18
I am running one Small Business Server 2003 on my network.  My server has a local ip behind an Instagate firewall.  Everything seems to be working fine but I see this error anywhere from 5-10 times a day for many different users.

Event Type:      Error
Event Source:      MSExchangeTransport
Event Category:      NDR
Event ID:      3008
Date:            11/5/2006
Time:            6:10:05 AM
User:            N/A
Computer:      Server
A non-delivery report with a status code of 5.0.0 was generated for recipient rfc822;Beth@exampledomain.com (Message-ID  <E1Ggfub-0002ld-00@exampledomain.com>).  
Cause:  This indicates a permanent failure. Possible causes :  1)No route is defined for a given address space. For example, an SMTP connector is configured, but this recipient address does not match the address spaces for which it routes mail.  2)Domain Name Server (DNS) returned an authoritative host not found for the domain.  3)The routing group does not have a connector defined û mail from one server in the routing group has no way to get to another routing group.    
Solution: Verify that this error is not caused by a DNS lookup problem, and then check the address spaces configured on your STMP connectors. If you are delivering Internet mail through an SMTP connector,  consider adding an address space of type SMTP with value ô*ö (an asterisk) to one of the SMTP connectors to make routing possible. Verify all routing groups are connected to each other through a routing group connector or another connector.

I have reviewed:

I have read:
And confirmed via telnet that I am NOT an Open SMTP Relay

I don't think spam is creating this error but I could be wrong.  Is this a DNS problem? Please help!!

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Expert of the Year 2007
Expert of the Year 2006

That looks like a DNS issue.
How is your DNS configured?

The best practise I use is to set the server to use itself ONLY for DNS, then if I need to use external DNS servers I set forwarders on the DNS Server applet. The forwarders are the ISPs DNS Servers.


Some of developers use fictitious email domains for testing their workflow application. They use the production smtp server for the same. In that case, these fictitious email domains will not have route and hence the MTA generates NDR for the same. Check with those users if they test any group ware based application


I am not a pro with DNS but this is how it looks to be setup.

On the Server, in the TCP/IP settings, the only DNS IP is the Server’s own local IP. (Gateway is still the Router’s IP, WINS is the Server’s local IP)  There is no alternate DNS Server address.

On the Server, in DNS Management, after I right click the Server-properties, under the “Interfaces” tab… “Only the following IP addresses:” is selected and the only IP is the IP of the Server itself.  Under the “Forwarders” tab… is the IP of the Router (which has both our ISPs DNS servers) and the IP of one of those two ISP DNS servers.

Should I add the other ISP’s DNS to the Forwarder?  Other than that it looks good to me.

~Sometimes I will get the MSExchangeTransport Error 3008 at 3am when no one is in the office.  I have not looked into fictitious emails created by an application.

Any ideas? Thanks!
Expert of the Year 2007
Expert of the Year 2006

I would take out the router from the list of forwarders and have just the ISPs DNS servers in there. Reduce the hops required.



I still get MSExchangeTransport 3008 and 3018 errors.  

What does this error mean to the email in my system?  Is mail not being sent? Does it retry until it is successful?  Any ideas on how to resolve this issue?

Thank you,
Expert of the Year 2007
Expert of the Year 2006

If you have diagnostics logging turned up, then every NDR that the server generates also generates an entry in the system viewer. You may want to review your diagnostics logging to ensure that you are not logging too much information.



Funny thing about the diagnostic logging… the MSExchangeTransport is set to None but still sends reports.  However, I would like to resolve the reports I get.  I came across a helpful web page (http://www.computerperformance.co.uk/exchange2003/exchange2003_NDR.htm) and added meaning to the two errors/status codes I am getting.  I confirmed that I am using our ISPs correct DNSs as our DNS forwarders.

MSExchangeTransport 3018
Status code of 5.4.0
Meaning: DNS Problem.  Check the Smart host, or check your DNS. It means that there is no DNS server that can resolve this email address.  Could be Virtual Server SMTP address.

MSExchangeTransport 3008
Status code of 5.0.0
Meaning: SMTP 500 reply code means an unrecognised command.  You get this NDR when you make a typing mistake when you manually try to send email via telnet. More likely, a routing group error, no routing connector, or no suitable address space in the connector.  (Try adding * in the address space)

Does this spark any ideas?

Thank you,


I forgot to ask… Should I have any SMTP Connectors?

I have the Default SMTP Virtual Server. (under server, protocols, smtp)

Then I have two SMTP Connectors:
Internet Mail SMTP Connector (SERVER3)
SmallBusiness SMTP connector

Expert of the Year 2007
Expert of the Year 2006
The Small Business SMTP Connector is created by the Small Business Server internet and email configuration wizard.
The other one could be a hang over from an Exchange 5.5 server.

My instinct is that the errors are nothing to worry about. Probably typos on the user's part. They certainly are not something that I go looking for through the event viewer.


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