Topic Last Modified: 2007-05-16

By default, SMTP Server blocks computers from relaying unwanted mail through the virtual server. To enable relay access through the Simple Mail Transfer Protocol (SMTP) virtual server, click Relay on the Access tab. By default, all computers are blocked except those that meet the authentication requirements designated in the Authentication dialog box, which you can view by clicking Authentication on the Access tab.

You can also allow messages to be relayed to a specific remote domain. For more information, see Configure Remote Domains. The domain setting overrides the SMTP virtual server setting.

Note:
If your virtual server is on the Internet, you shouldn't allow relaying to avoid propagating unsolicited e-mail.

Procedure

To remove relay restrictions from a virtual server

  1. In Microsoft Management Console, select the SMTP virtual server, and then click Properties on the Action menu.

  2. On the Access tab, under Relay restrictions, click Relay. The Relay Restrictions dialog box will open.

  3. Click either Only the list below or All except the list below.

  4. Click Add to open the Computer dialog box and add exceptions to the global access option that you chose in step 3.

You can specify the following options in the Relay Restrictions dialog box.

Option Description

Only the list below

Only the computers in the list can relay messages through the SMTP virtual server. This is set by default, together with Allow all computers which successfully authenticate to relay, regardless of the list above. Because the list is blank upon a fresh installation of Windows Server 2008, this means only authenticated users can relay mail by default.

All except the list below

All computers can relay messages through the SMTP virtual server, except those in the list.

Add and Remove

This option adds and removes entries to the list of those computers either granted or denied relay access.

Allow all computers which successfully authenticate to relay, regardless of the list above

This option allows computers that meet authentication requirements set in the Authentication dialog box to relay messages to the SMTP virtual server. This is set by default.