Resources | Microsoft Exchange Server 2003 - Recipient Filtering

Spam Soap service is designed to automatically create users for email addresses which are considered valid (250 SMTP reply code) and to deny email for users considered invalid (550 SMTP reply code). This is especially helpful to keep an accurate list of Users in the Spam Soap console and to generally process less email on your Exchange server. By default, Exchange 2003 will accept all email and then internally generate the Non Delivery Report and reject the email. The changes below will cause your Exchange server to reject the message toward the beginning of the SMTP session.

1. Open Exchange System Manager and go to the Properties of the Message Delivery. Then click Filter recipients who are not in the Directory.
   
2. Navigate to the Default SMTP Virtual Server Properties. Click the Advanced button, then Edit button. Now you can check the box to Apply Recipient Filter.
   

These tips are provided by Spam Soap at www.spamsoap.com