Messages that lose their business value after a specific amount of time are an important consideration with respect to potential failures.

Consider a weather reporting system that reports the current temperature every few minutes. How long is that data meaningful? Nobody seems to care what the temperature was 2 hours ago; they want to know what the temperature is now!

NServiceBus provides a method to cause messages to automatically expire after a given amount of time. Unlike storing this information in a database, you don't have to run any batch jobs or take any other administrative action to ensure that old data is discarded. You simply mark the message with an expiration date and when that time arrives, the message simply evaporates into thin air:

[TimeToBeReceived("01:00:00")]
public class RecordCurrentTemperatureCmd : ICommand
{
  public double Temperature { get; set; }
}

This example shows that the message must be received within one hour of being sent, or it is simply...