Configure Recipient Filtering
Recipient filtering can filter e-mail that is addressed to users who are not found in Active Directory. Any incoming mail addressed to an invalid recipient is then rejected, and the SMTP virtual server returns a "5.xx" error during the SMTP session.
You can also use recipient filtering to filter messages that are sent to any e-mail address (valid or invalid) within your organization. If the message is sent to any of the specified recipients, the e-mail is then rejected, and the SMTP virtual server returns a "5.xx" error during the SMTP session.
Recipient filtering is defined globally, but enabled on the SMTP virtual server on a per-IP address basis. Different groups of users can log on with any number of IP address/TCP port combinations. You can decide which combinations, and thus which users or groups, will have their messages filtered.
To configure recipient filtering, you must first create a recipient filter and then apply it at the SMTP virtual server level. The following sections explain how to perform each of these tasks:
Create a Recipient Filter
You can use recipient filtering to block e-mail that is destined to invalid recipients, based on an Active Directory lookup. You can also use recipient filtering to block e-mail to any recipients who are specified on the recipient filter list.
To create a recipient filter:
Start System Manager: On the Start menu, point to Programs, point to Microsoft Exchange, and then click System Manager.
Cannot Start the Application
You can manually start the application by following these instructions: On the Start menu, point to Programs, point to Microsoft Exchange, and then click System Manager.
Double-click Global Settings.
Right-click Message Delivery, and then click Properties.
Click the Recipient Filtering tab, and then click Add.
In Add Recipient, type the recipient's address and then click OK. The recipient address must conform to the following guidelines:
The recipient address must contain an @ symbol.
Display names must be entered in quotes with the @ symbol immediately following. Make sure there are no spaces between the quotes and the @ symbol.
Use *@domain name to denote all members of a domain, or simply type @domain name.
To filter e-mail that is sent to users who are not found in Active Directory, select the Filter recipients who are not in the Directory check box.
Caution Enabling this check box can potentially allow senders of unsolicited commercial e-mail to discover valid e-mail addresses in your Exchange organization, because during the SMTP session, the SMTP virtual server sends different responses for valid and invalid recipients.
Enable Recipient Filtering on a Virtual Server
When you enable recipient filtering on an SMTP virtual server, e-mail sent to any recipients on recipient filter is not accepted.
Recipient filtering is defined globally, but enabled at the SMTP virtual server on a per-IP address basis. Different groups of users can log on with any number of IP address/TCP port combinations. You can decide which combinations, and thus which users or groups, will have recipient filtering enabled for their messages.
Note Before you can enable recipient filtering on a virtual server, you must create a recipient filter.
To enable recipient filtering on a virtual server:
Start System Manager: On the Start menu, point to Programs, point to Microsoft Exchange, and then click System Manager.
Cannot Start the Application
You can manually start the application by following these instructions: On the Start menu, point to Programs, point to Microsoft Exchange, and then click System Manager.
Navigate to the SMTP virtual server.
Servers
Server
Protocols
SMTP
SMTP virtual server
Right-click the SMTP virtual server, and then click Properties.
On the General tab, click Advanced.
In Advanced, select the IP address to which you want to apply the message filter, and then click Edit.
In Identification, select the Apply Recipient Filter check box, and then click OK. In Advanced, under the Filter Enabled column, Yes appears.
To disable filtering, clear the Apply Recipient Filter check box.