The Receive Message Workflow Activity waits for receipt of a Blue Integrator Message.  Each Receive Port Message Activity is bound to a Receive Port in the Blue Integrator Explorer when configuring a Workflow.  This activity is towards the top of the Activity Palette in the Blue Integrator Workflow Designer.

To use this activity in a Workflow, you must set the Message parameter, by selecting from the drop-down list of configured Blue Integrator Messages.  On execution, this is the name of the Message variable that will contain the received Message.  The Activity will block until a Message is received, and supports asynchronous operation, so it can be contained within an EventDriven Activity.  The exception is that the first Receive Port Message Workflow Activity in a Workflow will not block, and will exit with an error if there is not a Message waiting – this is because Workflow Instances are triggered on receipt of a message bound to the first Receive Port Message Workflow Activity, and so necessarily there should be a Message waiting.

Optionally you can configure the CorrelationFilter property, to determine which future messages will be directed../Workflow Correlation.htm to this Workflow Instance.  See the Correlation topic for further details.