Understanding the Default Policy

By default, an SMTP policy exists for the domain *. This domain encompasses all messages that are destined for the Internet. All messages that Exchange sends to the Internet use the settings on this policy. You can view this policy in the details pane when you select Internet Message Formats in Exchange System Manager, as shown in the following figure.

Default SMTP policy for all Internet domains

A policy must exist for the * domain. This policy controls how messages are sent to all external domains. You can modify the properties on this policy.