Why Get-TransportAgent doesn't agree with the Exchange console

You disable a particular anti-spam agent - let's say the Content Filtering Agent - from the Exchange console.



Next, you use the Get-TransportAgent command to get the status of transport agents - and surprisingly the Content Filter Agent shows up as Enabled!



Why doesn't Get-TransportAgent agree with the Exchange console about the status of an agent?

Fellow MCT and Exchange geek David Elfassy blogged about it recently.

The Anti-Spam tab is located under the Organization Configuration | Hub Transport node in the console. Disabling an agent from the console prevents the agent on all transport servers in the Organization from taking any action. It's an Organization-wide or global setting.

The Get-TransportAgent command is transport server-specific. It shows the status of agents on a particular server. With the Org-wide configuration set to disabled, an agent enabled on a particular transport server behaves like a soldier instructed to fire but not kill. (May not be the best analogy - it doesn't exactly scare spam, and it doesn't do much else).

To draw a parallel to Exchange Server 2003, you can enable settings on a particular filter - e.g. Recipient Filtering, in Global Settings. However, you still have the flexibility of being able to enable/disable it on a per-SMTP virtual server basis. This is somewhat similar.

To get the global/Org-wide status of a particular filter, you need to use the corresponding command for that filter.
- For Content Filter Agent: Get-ContentFilterConfig
- For Recipient Filter Agent: Get-RecipientFilterConfig
- For Sender Filter Agent: Get-SenderFilterConfig
- For SenderID Agent: Get-SenderIDConfig
- For Protocol Analysis Agent: Get-SenderReputationConfig

If you've carefully looked at the above list, you're probably wondering why there's no mention of Connection Filtering Agent in it. The Connection Filtering Agent handles multiple tasks which are listed individually in the console.

To check the global setting for configuration of each, use the corresponding config command:
- For IP Block List: Get-IPBlockListConfig
- For IP Block List Providers: Get-IPBlockListProvidersConfig
- For IP Allow List: Get-IPAllowListConfig
- For IP Allow List Providers: Get-IPAllowListProvidersConfig

To "disable" an agent in Organization Configuration (equivalent of what you do in the console) using the shell, use the corresponding Set command, e.g.:

Set-ContentFilterConfig -Enabled $false

Next, let's take a look at how you can disable an agent on a transport server. Generally, if the Get-Blah command returns a property like Enabled: True, you can use Set-Blah -Enabled $false to disable it (You probably know where we're going with this by now... :). Not so for Get-TransportAgent. Its "Set" counter-part - Set-TransportAgent allows you to modify only one property -Priority. You can change the order in which these agents fire by changing their Priority.

You use the Disable-TransportAgent command to disable an agent on a transport server:

Disable-TransportAgent "Connection Filtering Agent"

No points for guessing the command used to enable a transport agent - Enable-TransportAgent