Gets or sets a value that specifies how long messages are valid. When this time has elapsed the message is placed in a dead-letter queue depending on the DeadLetterQueue setting.
Assembly: System.ServiceModel (in System.ServiceModel.dll)
Queued applications work in a disconnected manner. This means that the sending and receiving applications may not be running at the same time; therefore, a message sent by the sending application may not be processed immediately by the receiving application. Some messages contain information that is valid only for a certain period of time. If such a message is not delivered within that period of time, it no longer contains useful information and should be dropped. This property enables you to specify a time limit for how long a message is kept prior to delivery to the application queue. If this time limit elapses prior to the message being delivered to the application queue, the message is placed in the dead-letter queue if one is available (determined by the DeadLetterQueue property); otherwise, the message is dropped.