|Message:||Anti-spam agents are enabled, but the list of internal SMTP servers is empty. If there are any MTAs between this server and the Internet, populate this list by using the Set-TransportConfig cmdlet in the Exchange Management Shell.|
The Warning event indicates that Microsoft Exchange Server 2007 anti-spam agents are enabled and the list of internal Simple Mail Transfer Protocol (SMTP) servers is empty.
In some organizations, the Hub Transport server role or Edge Transport server role that is running connection filtering is installed on computers that don’t process SMTP requests directly on the Internet. In this scenario, the Exchange 2007 transport server is behind another front-end SMTP server that processes inbound messages directly from the Internet. The Connection Filter agent must be able to extract the correct originating IP address from the message. To extract and evaluate the originating IP address, the Connection Filter agent must parse the Received headers from the message and compare those headers with the known SMTP server in the perimeter network.
When an RFC-compliant SMTP server receives a message, the server updates the message’s Received header with the domain name and IP address of the sender. Therefore, for each SMTP server that is between the originating sender and the Exchange 2007 transport server, the SMTP server adds an additional Received header entry.
To resolve this warning, you must specify all internal SMTP servers on the transport configuration object in the Active Directory directory service forest before you run connection filtering.
Specify the internal SMTP servers by using the InternalSMTPServers parameter on the Set-TransportConfig cmdlet. For more information, see Set-TransportConfig.
For more information about how to configure connection filtering see Configuring Connection Filtering.
If you are not already doing so, consider running the tools that Microsoft Exchange offers to help administrators analyze and troubleshoot their Exchange environment. These tools can help you make sure that your configuration is in line with Microsoft best practices. They can also help you identify and resolve performance issues, improve mail flow, and better manage disaster recovery scenarios. Go to the Toolbox node of the Exchange Management Console to run these tools now. For more information about these tools, see Toolbox in the Exchange Server 2007 Help.