Mediator processes messages depending on the conditions specified in the routing rules. In some cases, a Mediator may not process an incoming message because the message does not satisfy any of the conditions specified in the routing rules. You can define a default routing rule for such messages. The default routing rule is executed when none of the conditions of other routing rules are satisfied.

A default routing rule is the same as the routing rules discussed in How to Create Static Routing Rules. The only difference between a default routing rule and other routing rules is that a default routing rule does not have any condition associated with it. Otherwise, a default routing rule is the same as other routing rules in every other aspect, such as target service, response handling, fault handling, and so on.