This article was previously published under Q324272
For a Microsoft Windows 2000 version of this article, see 310336.
This article describes how to configure a remote domain for an Internet Information Services (IIS) Simple Mail Transfer Protocol (SMTP) mail relay server.
IIS in Windows Server 2003 includes a full-featured SMTP virtual server that you can use to route mail on your internal network. The SMTP virtual server can also accept mail from the Internet. Although the SMTP Service does not include an easily accessible mechanism in which to retrieve mail, it can play a vital role in accepting mail from the Internet and relaying it to your SMTP/POP3 server. You can configure the SMTP virtual server to accept mail for the domain to which the computer belongs, and for other domains.
A stand-alone server that is running the SMTP Service provides a good measure of security because it acts as a layer of separation between the corporate mail server and inbound connections from the Internet. A stand-alone Windows Server 2003-based computer isolates the server from the Active Directory security boundaries of the internal network. You can configure the stand-alone SMTP virtual server to use the corporate mail server as a smart host. You can then configure the stand-alone SMTP virtual server to relay mail that is directed only to the remote domain. If you do this, all other mail is not relayed and is rejected.
How to Configure a Stand-Alone IIS SMTP Server to Relay to a Remote Domain
Start Internet Information Services Manager or open the Internet Information Services (IIS) snap-in.
Expand Server_name, where Server_name is the name of the server, and then expand Default SMTP Virtual Server.
Right-click Domains, point to New, and then click Domain.
Click Remote, and then click Next.
Type the name of the new remote domain in the Name box.
You can specify a single domain, or you can use an asterisk (*) as a wildcard character (the asterisk must be at the beginning of the name and be separated from the rest of the name by a period) to specify more than one domain. For example, if you want the remote domain to accept mail for other-domain.com and all its subdomains, use the name *.other-domain.com.
In the right pane, right-click the new remote domain that you just created, and then click Properties.
Click the General tab.
Under Select the appropriate settings for your remote domain, click to select the Allow incoming mail to be relayed to this domain check box to allow the SMTP server to act as a mail relay.
Under Route domain, click Forward all mail to smart host, and then type the IP address or the fully qualified domain name (FQDN) of the internal network's corporate mail server. If you use an IP address, make sure that you use brackets "" to enclose the IP address. For example, [nnn.nnn.nnn.nnn].
Stop and start the SMTP virtual server. To do so, right-click Default SMTP Virtual Server, and then click Stop. After the virtual server stops, right-click Default SMTP Virtual Server again, and then click Start.
After you configure the remote domain, all mail that is addressed to the remote domain name is relayed to the smart host that you configured. Mail that is not deliverable is stored in the Inetpub\Mailroot\Badmail folder.
For additional information about how to configure Microsoft SMTP Service local domains in Windows Server 2003, click the following article number to view the article in the Microsoft Knowledge Base:
323436 How To Configure Microsoft SMTP Service Local Domains in Windows Server 2003
For additional information about how to create additional SMTP Virtual Servers, click the following article number to view the article in the Microsoft Knowledge Base:
303707 How To Create additional SMTP Virtual Servers in Windows 2000
For additional information about how to create or delete a Microsoft SMTP Service domain, click the following article number to view the article in the Microsoft Knowledge Base:
303708 How To Create or Delete a Microsoft SMTP Service Domain in Windows 2000
For additional information about how to enable SMTP protocol logging for IIS, click the following article number to view the article in the Microsoft Knowledge Base:
303738 How To Enable SMTP protocol logging for Internet Information Services in Windows 2000
Microsoft Windows Server 2003, Standard Edition (32-bit x86), Microsoft Windows Server 2003, Enterprise Edition (32-bit x86), Microsoft Windows Server 2003, Enterprise x64 Edition, Microsoft Windows Server 2003, Datacenter Edition (32-bit x86), Microsoft Windows Server 2003, 64-Bit Datacenter Edition, Microsoft Internet Information Services 6.0