Recipient Filters Test

The Recipient Filter agent is an anti-spam agent that is enabled on computers that have the Microsoft Exchange server 2007/2010 Edge Transport server role installed.

The Recipient Filter agent blocks messages according to the characteristics of the intended recipient in the organization. The Recipient Filter agent can help you prevent the acceptance of messages in the following scenarios:

  • Nonexistent recipients:  You can prevent delivery to recipients that are not in the organization's address book. For example, you may want to stop delivery to frequently misused account names, such as or
  • Restricted distribution lists:   You can prevent delivery of Internet mail to distribution lists that should be used only by internal users.
  • Mailboxes that should never receive messages from the Internet:   You can prevent delivery of Internet mail to a specific mailbox or alias that is typically used inside the organization, such as Helpdesk.

The Recipient Filter agent acts on recipients that are stored in one or both of the following data sources:

  • Recipient Block list:   An administrator-defined list of recipients for which inbound messages from the Internet should never be accepted.
  • Recipient Lookup:   Verification that the recipient is in the organization. Recipient Lookup requires access to Active Directory directory service information that is provided by EdgeSync to Active Directory Application Mode (ADAM).

You can use this test to monitor the effectiveness of the Recipient Filter Agent. This test reports the number of messages that were rejected based on the Recipient Block List and the Recipient Lookup data sources.

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 the Hub/Edge 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

Recipients rejected by recipient validation

Indicates the number of recipients rejected per second by recipient validation.


One benefit of the Recipient Filter agent is the ability to verify that the recipients on an inbound message are in your organization before Exchange 2007/2010 transmits the message into your organization. The ability to verify recipients in your organization relies on a Recipient Lookup data source that is available to the Hub/Edge Transport server.

The value of this measure indicates the number of recipients who were rejected by this data source.

Recipients rejected by block list

Indicates the number of recipients rejected by block list per second.


The Recipient Block list is a list that is maintained by the Edge Transport server administrators. The Recipient Block list data is stored in the Edge Transport server instance of ADAM. You must enter blocked recipients on each Edge Transport server computer.

You can enter the recipients that you want the Recipient Filter agent to block in the Exchange Management Console on the Blocked Recipients tab of the Recipient Filtering Properties page. You use the Set-RecipientFilterConfig command in the Exchange Management Shell to enter recipients.