Topic Last Modified: 2006-07-07

The Microsoft® Exchange Server Analyzer Tool queries the Active Directory® directory service to determine whether the configured value for the msExchSmtpMaxOutboundMsgPerDomain attribute has been changed from the default value of 20. By default, the msExchSmtpMaxOutboundMsgPerDomain attribute is configured for a maximum of 20 outbound SMTP messages per connection. If the Exchange Server Analyzer finds that this attribute does not have a value of 20, a non-default configuration message is displayed.

The msExchSmtpMaxOutboundMsgPerDomain attribute represents the maximum number of messages per connection that can be sent by an SMTP virtual server on the Exchange server. For example, if an SMTP server has 35 messages to send to and the msExchSmtpMaxOutboundMsgPerDomain attribute is set at 20, two connections to the mail servers responsible for messages will be made. The first connection will send the maximum 20 messages, and a second connection will be made to send the remaining 15 messages.

Generally, there is no best practices recommendation for determining the correct value for this attribute. Each organization must determine for itself the appropriate value to set.

To set a maximum number of messages per connection

  1. Open Exchange System Manager.

  2. Expand Servers, expand an Exchange server, expand Protocols, and then expand SMTP.

  3. Right-click an SMTP virtual server (for example, Default SMTP Virtual Server) and then click Properties.

  4. Click Messages.

  5. The current value for the msExchSmtpMaxOutboundMsgPerDomain attribute is listed in the Limit number of connections to field. Change this field as needed, and then click OK to save your changes. Accepted values for this field include any whole number between 1 and 1999999999..

  6. Click OK to close the Properties dialog box of the SMTP virtual server.

For more information about SMTP virtual server settings, see the following Microsoft Knowledge Base articles: