Administrators can use Microsoft's Queue Viewer, which is part of the Exchange Management Console, to avoid mail flow issues within an Exchange Server 2007 organization. To access the Queue Viewer:
- Open the Exchange Management Console.
- Select the Toolbox container. At this point, the console's middle pane will display all available tools (Figure 1).
Figure 1. The Queue Viewer icon is listed in the Exchange Management Console's toolbox. (Click on image for enlarged view.)
- Double click on the Queue Viewer icon (Figure 2).
Figure 2. Queue Viewer on a lab server. (Click on image for enlarged view.)
Realistically, there may be up to five different types of queues listed in the Queue Viewer, and the message count probably wouldn't be zero. Queues displayed within the tool are server-specific; however, they're only located on servers that are hosting the Hub Transport Server role. You can see this in the Connect to Server link, found in the Actions pane.
When you click on this link, you can only connect to a Hub Transport server. One caveat is that Edge Transport servers also have queues. However, they are designed to be isolated from the rest of the Exchange organization, so you will have to view those queues from the copy of the Exchange Management Console running on the Edge Transport server.
In Exchange Server 2003, each SMTP virtual server had a corresponding folder on a New Technology File System (NTFS) volume that acted as a queue for that virtual server. But in Exchange Server 2007, queues are database-driven. By default, the queue database is located in the C:\Program Files\Microsoft\Exchange Server\Transport Roles\data\Queues folder (Figure 3). The main database file is MAIL.QUE. Despite the .QUE extension, the database is in the standard extensible storage engine format.
By default, transaction log files, checkpoint files and reserve log files are also stored in the same folder as the database. Like other Exchange Server databases, the message queue database benefits from being placed on a high-speed array. I also recommend placing transaction logs on a separate volume for fault tolerance. Moving the message queue database and its log files requires some advanced planning.
Figure 4 shows another screen capture of the Exchange 2007 Queue Viewer on a lab server. As you can see in the figure, the Queue Viewer currently displays two queues.
The queue shown at the top of the list is a remote delivery queue. The other queue shown in the figure is the submission queue. The submission queue is the only queue that remains visible on any Edge Transport or Hub Transport server.
Options for interacting with a queue are basically the same, regardless of its type. To view a queue's contents, select the queue and click on the Messages tab, as shown in Figure 5. This tab lists all of the messages that are currently in the queue. You can use the various links from the column on the right to suspend the queue or remove individual messages with or without sending a non-delivery report.
The Messages tab offers some basic information about each individual message. You can see a message's status, size and Spam Confidence Level (SCL) rating. But if you're trying to decide whether or not to remove a message from the queue, you may want to get more detailed information it. To do so, select the message and click the Properties link found in the right column. You'll see a dialog box similar to that in Figure 6.
The Recipient Information tab displays message recipients, even though they're also listed on the last line of the General tab. For example, the last line of the Properties sheet displays that the recipient is an Exchange public folder database.
Message queues are designed to use circular logging. Log files can be overwritten once they have been committed. Although Exchange Server circular logging is designed to conserve disk space, it's extremely important that the volume containing the log files always has at least 4 GB of free space. When disk space on the volume containing the message queue's log files is low, performance is greatly affected and messages take longer to pass through the queues.
Monitor mail flow with the Exchange Server 2007 Queue Viewer tool
Home: Monitor mail flow with the Exchange Server 2007 Queue Viewer tool
Part 1: Using Queue Viewer in Exchange 2007 to prevent mail flow problems
Part 2: Understanding message queues in Exchange 2007 Queue Viewer
Brien M. Posey, MCSE
ABOUT THE AUTHOR: Brien M. Posey, MCSE, is a Microsoft Most Valuable Professional for his work with Exchange Server, and has previously received Microsoft's MVP award for Windows Server and Internet Information Server (IIS). Brien has served as CIO for a nationwide chain of hospitals and was once responsible for the Department of Information Management at Fort Knox. As a freelance technical writer, Brien has written for Microsoft, TechTarget, CNET, ZDNet, MSD2D, Relevant Technologies and other technology companies. You can visit Brien's personal Web site at http://www.brienposey.com.
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