Users do not receive meeting requests after you configure IPS on a SonicWALL firewall device in an Exchange Server 2003 organization

In a Microsoft Exchange Server 2003 organization, you configure the Intrusion Prevention Service (IPS) on a SonicWALL firewall device that provides access to the Internet. After you do this, users do not receive meeting requests from external domains.

Additionally, senders of the meeting requests receive a non-delivery report (NDR) message that resembles the following message:The following events are logged on the SMTP server that tries to connect to the Exchange server behind the SonicWALL firewall device:

Event ID : 7010
Source : MSExchangeTransport
Event Type : Error
Computer: Server_Name
Description : This is an SMTP protocol log for virtual server ID 1, connection #2406. The client at "IP_Address" sent a "rcpt" command, and the SMTP server responded with "501 5.5.4 Invalid Address ". The full command sent was "rcpt TO:<>". This will probably cause the connection to fail.

Event ID : 7004
Event Source : MSExchangeTransport
Event Type : Error
Computer : Server_Name
Description : This is an SMTP protocol error log for virtual server ID 1, connection #2347. The remote host "Server_Name.domain.com", responded to the SMTP command "Command_Name" with "504 Need to authenticate first ". The full command sent was "Command_Name ". This will probably cause the connection to fail.

This problem occurs because the IPS on a SonicWALL firewall device blocks meeting requests that reach its interface.

To resolve this problem, contact SonicWALL. For information about how to obtain support for SonicWALL products, visit the following SonicWALL Web site: Microsoft provides third-party contact information to help you find technical support. This contact information may change without notice. Microsoft does not guarantee the accuracy of this third-party contact information.
Additionally, you must install the security update that is described in the following Microsoft Security Bulletin to help protect the Exchange server:

The third-party products that this article discusses are manufactured by companies that are independent of Microsoft. Microsoft makes no warranty, implied or otherwise, regarding the performance or reliability of these products.