MSExchangeTransport 2021

This article provides an explanation and possible resolutions for a specific Exchange event. If you don't find what you’re looking for here, try searching Exchange 2010 Help.

Details

Explanation

This event indicates that a message delivery failure occurred between the Send connector on a Microsoft Exchange Server 2010 Transport server and another SMTP server. In Exchange 2010, the SMTPSend component is the transport component that sends messages from the Delivery Queue to other destinations. This event is triggered when the SmtpSend component cannot transfer routing destination information (RDST) to the destination SMTP server.

You may experience this issue if the following conditions are true:

• The message requires support for the XRDST extended SMTP verb

• The remote server does not support XRDST

Alternatively, this issue may occur if the following conditions are true:

• The sending server is running Exchange 2010 or Microsoft Exchange Server 2007

• The message destination is a public folder on a receiving server that is running Microsoft Exchange Server 2003.

• The XEXCH50 verb is disabled on the Exchange 2003 SMTP server

When Exchange 2010 or Exchange 2007 send messages to a public folder, they store additional message information in the XEXCH50 blob. In a pure Exchange 2010 or Exchange 2007 organization, the XEXCH50 verb can be disabled. In this scenario, Exchange 2010 and Exchange 2007 use the XRDST verb to store the public folder information. Exchange 2003 does not support XRDST.

Therefore, when the Exchange 2003 SMTP server does not advertise XEXCH50, Exchange 2010 tries to send the information by using XRDST. Because Exchange 2003 does not support this verb, the message cannot be sent.

User Action

To troubleshoot this issue, do one or more of the following:

• Review the Application log and System log on your Exchange 2010 servers for related events. For example, events that occur immediately before and after this event may provide more information about the root cause of this error.

• Log on to the remote SMTP server by using the telnet command to port 25. Use the EHLO command to return a list of extended SMTP verbs that the server supports. Determine whether the XRDST and/or XEXCH50 keywords are advertised.

• If the destination server is running Exchange 2003, restore support for XEXCH50. To do this, run the Microsoft Exchange Best Practices Analyzer on the server. The Best Practices Analyzer returns a list of DLL files that must be registered to support XEXCH50.

• If the destination server is running Exchange 2010 or Exchange 2007, run the Get-ReceiveConnector "ConnectorName" | Format-List command to determine whether the connector supports XRDST.

• Use the Set-ReceiveConnector cmdlet to enable XRDST on the remote SMTP Receive connector. For more information, see Set-ReceiveConnector.

• You may want to increase diagnostics logging to log the components in the transport pipeline. To increase diagnostics logging for the Transport components, follow these steps:

  1. In the Exchange Server 2010 Management Console, expand Server Configuration, and then click Hub Transport.

     Note   For an Edge Transport server, click Edge Transport.

  2. In the Actions pane, click Manage Diagnostic Logging Properties for the appropriate server.

  3. Expand MSExchangeTransport.

  4. Click the following components, and then click Expert, then click Configure for each component:

  • Smtpreceive

  • Smtpsend

  • DSN

  • Components

  • Remote Delivery

  • Categorizer

• Resolve your issue by using self-support options, assisted support options, and other resources. You can access these resources from the Exchange Server Solutions Center. From this page, click Self-Support Options in the navigation pane to use self-help options. Self-help options include searching the Microsoft Knowledge Base, posting a question at the Exchange Server forums, and other methods. Alternatively, in the navigation pane, you can click Assisted Support Options to contact a Microsoft support professional. Because your organization may have a specific procedure for directly contacting Microsoft Product Support Services, be sure to review your organization's guidelines first.

For more information about the transport pipeline in Exchange 2010, see the following topics:

• Understanding Transport Pipeline

• Exchange 2010 Transport Architecture Diagrams Available for Download

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