Configuring SMTP Message Filtering Options


Topic Last Modified: 2005-04-15

Although you configure SMTP message filtering options in the Message Delivery Properties dialog box, you must enable the filtering options on the individual SMTP virtual servers where you want to apply the filtering. Exchange applies these filters during the SMTP session when a remote SMTP server connects to the SMTP virtual server.

In Exchange 2003, you can configure sender filtering, connection filtering, and recipient filtering. Enabling filtering on an SMTP virtual server causes the virtual server to check the enabled filters when another SMTP server tries to send mail into the organization.

Exchange applies SMTP message filters only to messages sent from external SMTP servers. Exchange does not apply SMTP message filters when servers send messages between themselves in an Exchange organization. This is because Exchange servers automatically authenticate with each other and filter only mail that is submitted anonymously.