Event ID 4000 is logged when an SMTP server that is configured to use the Integrated authentication method negotiates GSSAPI authentication with an Exchange 2007 receive connector that is also configured to use the Integrated Authentication method

Consider the following scenario:

• On an Exchange 2007 HUB Transport server, you configure an Exchange 2007 receive connector to use the Integrated authentication method.
• A Windows Server 2003 SMTP server on Internet Information Services (IIS) submits e-mail messages to the Exchange 2007 server.
• This Windows Server 2003 SMTP server is also configured to use the Integrated authentication method.

In this scenario, the SMTP server cannot negotiate Generic Security Services API (GSSAPI) authentication with the Exchange 2007 receive connector. Therefore, the e-mail messages cannot be delivered to the Exchange 2007 server. Additionally, the following event is logged in the System log:

Event Type: Warning
Event Source: smtpsvc
Event Category: None
Event ID: 4000
Description: Message delivery to the remote domain 'domain.com' failed for the following reason: The remote SMTP service rejected AUTH negotiation. � For more information, see Help and Support Center at http://go.microsoft.com/fwlink/events.asp.

To resolve this problem, install Exchange Server 2007 Service Pack 1. For more information about Exchange Server 2007 Service Pack 1, click the following article numbers to view the articles in the Microsoft Knowledge Base:

Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.

For more information about the Integrated authentication method, visit the following Web site: