My Exchange server (SBS2003) seems to have developed a problem in the last few days. This server is servicing a small number of users (<10) and has been working properly for a few years. In the last 72 hours, the Exchange server is generating the "MSExchangeTransport NDR 3018" error for every email address that one user tries to send to. All other users are having no problems sending or receiving, and this user can receive messages with no problems. This user can also send and receive using an independent POP3 account that is setup on his instance of MS Outlook.
Here is the error message generated by the server everytime this user sends an email message through the server:
Event Type: Error
Event Source: MSExchangeTransport
Event Category: NDR
Event ID: 3018
Time: 12:33:58 PM
A non-delivery report with a status code of 5.4.0 was generated for recipient rfc822;firstname.lastname@example.org (Message-ID <FDDA08E3FDE24147AE765C69B
Causes: This message indicates a DNS problem or an IP address configuration problem
Solution: Check the DNS using nslookup or dnsq. Verify the IP address is in IPv4 literal format.
For more information, click http://www.microsoft.com/contentredirect.asp
0000: ef 02 04 c0 ï..À
Here is the error message that the user receives in return:
From: System Administrator
Sent: Wednesday, July 08, 2009 12:42 PM
Subject: Undeliverable: test message
Your message did not reach some or all of the intended recipients.
Subject: test message
Sent: 7/8/2009 12:42 PM
The following recipient(s) could not be reached:
email@example.com on 7/8/2009 12:42 PM
The destination server for this recipient could not be found in Domain Name Service (DNS). Please verify the email address and retry. If that fails, contact your administrator.
I have tried rebooting the workstation and the server with no luck.
Please let me know what suggestions you may have.