Correlation is used throughout BizTalk Server Messaging and Orchestration engines. In many cases, it is automatic and there is little or nothing you need to do to take advantage of it. BizTalk promotes the required properties for you without you having to explicitly configure which properties from which property schemas to use. Such examples are when using a Request-Response or Solicit-Response Port, when using a Self-correlated Binding or Partner Orchestration Binding. In these cases, correlations are created for you, in the engine, without you explicitly having to define the properties and the values of those properties needed to make sure that the second message gets routed back.

Correlation subscriptions are instance subscriptions, that is, they do not exist in sync with the status of an Orchestration (when it is Stopped or Started), and the Orchestration does not activate a new instance when met; instead, it exists only until it is fulfilled and the message gets...