Exchange Extensible Agents Test

Transport agents let you install custom software, created by Microsoft, by third-party vendors, or by your organization, on a computer that is running Microsoft Exchange server 2007/2010. This software can then process e-mail messages that pass through the transport pipeline on a Hub Transport server or Edge Transport server. Custom transport agents provide additional functionality to Exchange 2007/2010, such as anti-spam or antivirus programs or any transport function that your organization may require.

Delays in e-mail processing by the transport agents and flaws while performing anti-spam /anti-virus activities may affect the stability and security of Exchange. By periodically checking how the agents process e-mail messages, you can easily spot processing bottlenecks and security lapses. This test does just that.

Target of the test : A server configured with the Hub Transport role

Agent deploying the test : An internal agent

Outputs of the test : One set of results for theHub Transport server being monitored.

Configurable parameters for the test
Parameters Description

Test Period

How often should the test be executed.


Indicates the IP address of the Hub Transport server.


The port number of the Hub Transport server. By default, this is 691.

Measurements made by the test
Measurement Description Measurement Unit Interpretation

Agent processing time

Indicates the time taken by the transport agent per event for processing e-mail messages.


Ideally, the value of this measure should be low. A high value indicates that the agent is taking too long a time to process e-mail messages. The reason for this needs to be investigated. Sustained higher latencies may indicate a hung agent.

Total agent invocations

Indicates the total number of agent invocatins since last restart.