Configure Transport Rules
Transport rules are configured by using a wizard, similar to the wizard that Outlook uses for mailbox rules. When you configure transport rules, you should define the following elements:
- Conditions. Transport rule conditions indicate which email message attributes, headers, recipients, senders, or other message parts Exchange Server uses to identify the email messages to which it applies a transport rule action. If the email message data that the condition is inspecting matches the condition’s value, Exchange Server applies the rule, as long as the condition does not match an exception. You can configure multiple transport rule conditions to narrow the rule’s scope to specific criteria. You also can decide not to apply any conditions, which means that the transport rule then applies to all messages. There is no limit to the number of conditions that you can apply to a single transport rule.
Note: If you configure multiple conditions on the same transport rule, all of the conditions must be met for the transport rule to apply to a particular email message. When you specify multiple values on a single condition, the condition is satisfied if at least one of the values is met.
- Actions. Exchange Server applies actions to email messages that match the conditions and for which no exceptions are present. Each action affects email messages in a different way, such as redirecting the email message to another address or dropping the message.
- Exceptions. Exceptions determine which email messages to exclude from an action. Transport rule exceptions are based on the same predicates that you use to create transport rule conditions. Transport rule exceptions override conditions and prevent Exchange Server from applying a transport rule action to an email message, even if the message matches all configured transport rule conditions. You can configure multiple exceptions on a transport rule to expand the criteria for which the Exchange server should not apply a transport rule action.
Note: If you configure multiple exceptions on the same transport rule, only one exception must match for the transport-rule action to be canceled. When you specify multiple values on a single exception, the exception is satisfied if at least one of the values is met.
- Predicates. Conditions and exceptions use predicates to define which part of an email message the conditions and exceptions examine, to determine whether Exchange Server should apply the transport rule to that message. Some predicates examine the “To:” or “From:” fields, whereas other predicates examine the subject, body, or attachment size. To determine whether Exchange Server should apply a transport rule to a message, most predicates require that you specify a value that the predicates use to test against the message.