Topic Last Modified: 2013-02-22
Priority queuing is a feature of Microsoft Exchange Server 2013 that enables the message priority that's configured by the sender in Microsoft Outlook or Outlook Web Access to influence the processing of the message by the Transport service on the Mailbox server. When priority queuing is enabled, High priority messages are transmitted to their destinations before Normal priority messages, and Normal priority messages are transmitted to their destinations before Low priority messages. For more information, see Priority Queuing.
What do you need to know before you begin?
- Estimated time to complete: 15 minutes
- Exchange permissions don't apply to the procedures in this
topic. These procedures are performed in the operating system of
the Exchange Server.
- Changes you save to the EdgeTransport.exe.config application
configuration file are applied after you restart the Microsoft
Exchange Transport service.
- When you restart the Microsoft Exchange Transport service, mail
flow on the server is temporarily interrupted.
- Any customized per-server settings you make in Exchange XML
application configuration files, for example, web.config files on
Client Access servers or the EdgeTransport.exe.config file on
Mailbox servers, will be overwritten when you install an Exchange
Cumulative Update (CU). Make sure that you save this information so
you can easily re-configure your server after the install. You must
re-configure these settings after you install an Exchange CU.
- For information about keyboard shortcuts that may apply to the
procedures in this topic, see Keyboard Shortcuts in
the Exchange Admin Center.
Use the Command Prompt to enable and configure priority queuing in the EdgeTransport.exe.config file
- In a Command prompt window, open the EdgeTransport.exe.config
application configuration file in Notepad by running the following
- Find the following keys in the
<add key="PriorityQueuingEnabled" value="false" /> <add key="MaxPerDomainHighPriorityConnections" value="3" /> <add key="MaxPerDomainNormalPriorityConnections" value="15" /> <add key="MaxPerDomainLowPriorityConnections" value="2" /> <add key="HighPriorityMessageExpirationTimeout" value="8:00:00" /> <add key="NormalPriorityMessageExpirationTimeout" value="2.00:00:00" /> <add key="LowPriorityMessageExpirationTimeout" value="2.00:00:00" /> <add key="HighPriorityDelayNotificationTimeout" value="00:30:00" /> <add key="NormalPriorityDelayNotificationTimeout" value="4:00:00" /> <add key="LowPriorityDelayNotificationTimeout" value="8:00:00" /> <add key="MaxHighPriorityMessageSize" value="250KB" />
<add key="PriorityQueuingEnabled" value="true" />
- When you are finished, save and close the
- Restart the Microsoft Exchange Transport service by running the
net stop MSExchangeTransport && net start MSExchangeTransport
How do you know this worked?
To verify that you have successfully enabled and configured priority queuing, do the following:
- Verify the PriorityQueueinEnabled key in the
EdgeTransport.exe.config file has the value
- Use Outlook to create a high priority test message that's
larger than the value specified by the
MaxHighPriorityMessageSize key, and verify the message
arrives as a normal priority message.
- Try to verify that higher priority messages arrive before lower
priority messages sent to the same recipient or destination. You
can try to use multiple mailboxes to send multiple, similar test
messages with different priority values to the same recipient