XFOR: How to Stop Internet Mail Service from Relaying Junk E-mail Without Preventing Other Mail Services

This article describes how to configure the Microsoft Exchange Server Internet Mail Service to stop relaying junk e-mail (spam). This procedure does not prevent Post Office Protocol version 3 (POP3) clients and Internet Message Access Protocol 4 (IMAP4) clients from sending SMTP messages.

To configure the Microsoft Exchange Server Internet Mail Service to stop relaying unwanted mail, follow the instructions in the following Microsoft Knowledge Base article:

This article describes how to enable specific Internet Protocol (IP) addresses or users to relay SMTP messages by using the Routing Restrictions tab. When you follow the procedure in this article, you may inadvertently configure the Internet Mail Service so that POP3 and IMAP4 users are prevented from sending messages to the Internet.

If all POP3 and IMAP4 users connect from the same IP addresses or IP subnets, click to select the Hosts and clients with these IP addresses check box on the Routing Restrictions tab. If you add the respective IP addresses or subnets, the clients are able to send Internet messages.

If you click to select the Hosts and clients that authenticate check box, you must configure clients that connect to this service to send Internet messages. Each client profile must be set up to log on to the outgoing mail server.

To enable outgoing server authentication in Microsoft Outlook Express, follow these steps:

1. Open the properties of the default Internet account, and then click the Servers tab.
2. In the Incoming Mail Server box, verify that the user account information is in this format: domain\accountname. This information should be followed by the domain account password.
3. In the Outgoing Mail Server box, click to select the My server requires authentication check box, and then click the Settings button.
4. Click either the Use same settings as my incoming mail server check box, or specify an additional account and password to use that is different from the incoming mail server's account and password.
5. Click OK to save the settings.

POP3 and IMAP4 users are now able to send Internet messages, and the security settings to prevent junk e-mail remain intact.

For additional information, click the article number below to view the article in the Microsoft Knowledge Base: