All outbound Internet mail may be returned with a message that is similar to the following:
Your message did not reach some or all of the intended recipients.
Sent: 2/13/2001 11:29 AM
The following recipient(s) could not be reached:
c=US;a= ;p=org;o=site;dda:SMTPfirstname.lastname@example.org; on 2/13/2001 11:33 AM
The e-mail system was unable to deliver the message, but did not report a specific reason. Check the address and try again. If it still fails, contact your system administrator.The MTS-ID of the original message is:c=US;a= ;p=org;l=MAILSERVER-010213172832Z-2385
MSEXCH:IMS:org:site:MAILSERVER 3902 (000B099C) Host Unknown
This issue can occur if the Microsoft Windows 2000-based Domain Name System (DNS) server that Exchange 2000 or Exchange Server 2003 is using contains a forward lookup zone for the root domain (.). When Exchange 2000 or Exchange 2003 searches for an MX record to deliver mail, Exchange 2000 or Exchange 2003 queries the DNS server. The DNS server has no knowledge of MX records on the Internet or other DNS servers that might have those records, so Exchange 2000 or Exchange 2003 is unable to route any outbound messages.
If you do not have access to the DNS Console and cannot make changes to the configuration of your DNS server, or if you want to keep DNS resolution local to your internal network and want to retain the forward lookup zone for the root (.) domain, use the following procedure to work around this issue:
- Go to the server that is running Exchange 2000 or Exchange 2003.
- Open the properties of the SMTP virtual server.
- Click the Delivery tab, click Advanced, and then click Configure to configure external DNS servers. Specify the address of one or more DNS servers with external name resolution.
After you perform these steps, Exchange 2000 or Exchange 2003 should query the specified DNS servers to route outbound mail through this SMTP virtual server. If you have more than one server that is running Exchange 2000 or Exchange 2003, you must follow this process on every server that is running Exchange 2000 or Exchange 2003.
For more information about the root zone in Windows 2000, click the following article number to view the article in the Microsoft Knowledge Base:
How to remove the root zone (dot zone)