XFOR: No Error When IMC Starts and Configured for DNS

• Microsoft Exchange Server, version 4.0

SYMPTOMS

If the Internet Mail Connector (IMC) is configured to use a Domain Name Service (DNS) and there is no resolver, the IMC starts without logging an error in the event log.

RESOLUTION

If the DNS is not available, there are other ways to resolve the address:

1. The Internet Mail Connector will use the DNS.

2. If there is no DNS, the Internet Mail Connector will read the local Hosts file.

3. If the local Hosts file does not contain the address, the Internet Mail Connector uses the WINS service to resolve the address. If WINS doesn’t return an answer to the query, a non-delivery report (NDR) will be sent back to the sender of the message.

STATUS

Microsoft has confirmed this to be a problem in Microsoft Exchange Server version 4.0. We are researching this problem and will post new information here in the Microsoft Knowledge Base as it becomes available.

MORE INFORMATION

DNS is the method by which an e-mail address is resolved to the TCP/IP address of a host that can relay the message to the correct user.

REFERENCES

Refer to the "Delivering Messages Using DNS" procedure in Chapter 11 of the Microsoft Exchange "Administrator's Guide."

1. On the Site menu, click Configuration. Click Connections, then open the Internet Mail Connector.

2. Select the Connections tab.

3. Under Message Delivery, select "Use DNS to route all outbound messages using domain name service queries." This also includes queries using a hosts file or WINS.

   The hosts file is located in the Winnt\System32\Drivers\Etc directory.