Message Queuing

The Message Queuing (MSMQ) service is a messaging infrastructure and development tool that creates distributed messaging applications for the Windows operating system. Such applications can communicate across heterogeneous networks and send messages between computers that may be temporarily unable to connect to each other. This service provides guaranteed message delivery, efficient routing, security, and priority-based messaging.

For remote reading, Message Queuing 4.0 uses encrypted RPC by default. In situations where encrypted RPC cannot be used, (for example, where a workgroup computer is part of the remote read process), the message is passed to the remote computer as plaintext and message security is not guaranteed. A plaintext message that has reached its destination queue can be read only by users who have the necessary access rights to read messages from the queue.

We recommend that servers enable Message Queuing 4.0 in secured remote reading mode. In secured remote reading mode, the computer only listens to the secure remote read interface. The effect of this is that only Message Queuing 4.0 and Message Queuing 3.0 on servers running Windows Server 2003, Windows Server 2008, or Windows Server 2008 R2 can remotely receive messages from queues on the computer. Remote reads from MSMQ 1.0 client computers, MSMQ 2.0 client computers, and Message Queuing 3.0 client computers running Windows XP are not supported. For information about enabling your server to use only the secured mode, see Enable Secured Remote Read.

If the Message Queuing service stops, distributed messages are unavailable. If you disable this service, any services that explicitly depend on it do not start. Also, the COM+ Queued Components service, some functionality of Windows Management Instrumentation (WMI), and the Message Queuing Triggers service are affected.

Message Queuing is an optional feature in Windows 7 and Windows Server 2008 R2. It is not installed or enabled by default. It can be added through the Turn Windows Features on or off dialog box in the Programs area of Control Panel. When this service is installed, its default startup type is Automatic. When the Message Queuing service is started it logs on using the Network Service account by default.

The Message Queuing service is dependent upon the following system components:

  • Message Queuing Access Control
  • Remote Procedure Call (RPC)
  • DCOM Server Process Launcher
  • RPC Endpoint Mapper
  • Windows Event Log

The following services are dependent upon the Message Queuing service:

  • Message Queuing Triggers
  • Net.Msmq Listener Adapter

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