Backlogged MTA Queue

Run the Performance Monitor Server Queues chart view to determine whether the MTA queue is the bottleneck. This chart view shows how much traffic the MTA is transmitting to and from other servers, sites, or organizations. If the MTA is causing the mail to be delayed, the Work Queue Length counter will be high and the chart will look similar to the one in the following illustration.

If the MTA queue is backlogged and there is high disk activity, the disk containing the databases is causing the problem. The queue can be backlogged because the MTA cannot write to disk quickly enough.

To improve the speed of message processing in the MTA queue do any of the following:

• Restrict the amount or type of mail users can send.
• Add more disks to the stripe set.
• Use multiple disk controllers.
• Add one or more caching disk controllers that cache read and write operations.