Set a Fully Qualified Domain Name
At startup, the name that is designated on the
Network Identification tab of the
System Properties dialog box is automatically used for the fully qualified domain name (FQDN). If you change the name (either manually or by joining a Microsoft Windows 2000 domain), the new name is automatically used for the FQDN the next time the computer is restarted. You do not have to perform any action to update the FQDN for the virtual server.
To override the automatic use of the computer and domain names on the
Network Identification tab, change the FQDN in the
Advanced Delivery dialog box (this is accessed through the
Delivery tab). The Microsoft SMTP Service can then use the designated name instead of the name that is specified on the
Network Identification tab. To set the FQDN, follow these steps:
- In the MMC, click to select the SMTP virtual server, and then click Properties on the Action menu.
- On the Delivery tab, click Advanced to open the Advanced Delivery dialog box.
- For Fully-qualified domain name, type the FQDN.
Configure a Smart Host
You can route all outgoing messages for remote domains through a smart host instead of sending them directly to the domain. This permits you to route messages over a connection that may be more direct or less costly than other routes. The smart host is similar to the route domain option for remote domains. The difference is that after a smart host is designated, all outgoing messages are routed to that server. With a route domain, only messages for the remote domain are routed to a specific server.
If you set up a smart host, you can still designate a different route for a remote domain. The route domain setting overrides the smart host setting. To set up a smart host, follow these steps:
- In the MMC, click to select the SMTP virtual server, and then click Properties on the Action menu.
- On the Delivery tab, click Advanced to open the Advanced Delivery dialog box.
- In Smart host, type the name of the smart host server. You can type a string to represent a name, or you can type an IP address.
- If you want the Microsoft SMTP Service to try to deliver remote messages directly before it forwards them to the smart host server, click to select the Attempt direct delivery before sending to smart host check box. The default is to send all remote messages to the smart host, not to try direct delivery.
NOTE: You can identify the smart host by the FQDN or by an IP address. Note that if you change the IP address, you must also change it on every virtual server. If you use an IP address, enclose it in brackets ([]) to increase system performance. Microsoft SMTP Service checks first for a server name, then an IP address. The brackets identify the value as an IP address, so the DNS lookup is bypassed.
Enable a Reverse DNS Lookup
If you select this option, Microsoft SMTP Service tries to verify that the IP address of the client matches the host or domain that is submitted by the client in the EHLO or HELO command.
NOTE: Because this feature verifies addresses for all incoming messages, its use can affect Microsoft SMTP Service performance. Clear the check box to disable the feature.
If the reverse DNS lookup is successful, the Received header remains intact. If the verification is unsuccessful, "unverified" appears after the IP address in the Received header of the message. To enable reverse DNS lookup, follow these steps:
- In the MMC, click to select the SMTP virtual server, and then click Properties on the Action menu.
- On the Delivery tab, click Advanced to open the Advanced Delivery dialog box.
- Click to select the Perform reverse DNS lookup on incoming messages check box.