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DeadLetterQueue Enumeration

Specifies the type of dead-letter queue to be used.

Namespace:  System.ServiceModel
Assembly:  System.ServiceModel (in System.ServiceModel.dll)

public enum DeadLetterQueue

Member nameDescription
NoneNo dead-letter queue is to be used.
SystemUse the system-wide, dead-letter queue.
CustomCustom dead-letter queue.

The dead-letter queue is a queue on the queue manager of the sending application for expired messages that have failed to be delivered. The DeadLetterQueue enumeration specifies the type of dead-letter queue to use. The values are:

  • None: No dead-letter queue is required. If a message fails delivery, no record of it is maintained in the dead-letter queue. This is the default value when ExactlyOnce is set to false.

  • System: The system-wide, dead-letter queue is used to record messages that fail delivery. MSMQ has a transactional, system, dead-letter queue and a non-transactional, system, dead-letter queue to record expired messages that failed delivery from transactional and non-transactional queues, respectively. This is the default value when ExactlyOnce is set to true.

  • Custom: The queue specified in the CustomDeadLetterQueue is used to record messages that fail delivery.

A message can fail to reach the receiving application for any of the following reasons:

  • A transactional message is sent to a non-transactional queue.

  • A non-transactional message is sent to a transactional queue.

  • An unauthenticated message is sent to a queue that accepts only authenticated messages.

  • An unencrypted message is sent to a queue that accepts only encrypted messages.

  • The message's time-to-live value expires before the message is delivered to a receiver.

  • The message storage quota of the target computer or the storage quota of the destination queue is exceeded, or there is no available storage space on the target computer when the message arrives.

  • The sender does not have the access rights required to place the message in the destination queue.

  • The digital signature attached to the message is not valid.

  • An encrypted message cannot be decrypted by the destination queue manager.

  • The destination queue is purged or deleted before the message is retrieved.

.NET Framework

Supported in: 4, 3.5, 3.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.