Assume that you apply Update Rollup 1 for Microsoft Exchange Server 2010 Service Pack 2 in your environment. The Exchange server receives a message that contains invalid character sets on the Subject line. For example, the Subject line contains the GB2313 charset (charset value is 134) or the CHINESEBIG5 charset (charset value is 136). In this situation, the Microsoft Exchange Transport service (EdgeTransport.exe) crashes, and the message is not delivered. Additionally, the following events are logged in the Application log:

Log Name: Application
Source: MSExchange Common
Date: Date
Event ID: 4999
Task Category: General
Level: Error
Keywords: Classic
User: N/A
Computer: Computer
Description:Watson report about to be sent for process id: Process ID, with parameters: E12, Build Type, Version Number, edgetransport, M.Exchange.Transport, M.E.T.C.MExEvents.HandleAgentExchangeExceptions, System.InvalidOperationException, XXXX, Version Number.

Log Name: Application
Source: MSExchangeExtensibility
Task Category: MExRuntime
Event ID: 1051
Level: Warning
Agent 'Outbound Trust Agent' caused an unhandled exception 'InvalidCharsetException: Character set name (Bad Charset Name Here) is invalid or not installed.' while handling event 'OnCategorizedMessage'

Log Name: Application
Source: MSExchangeTransport
Event ID: 10003
Task Category: PoisonMessage
Level: Error
The transport process failed during message processing with the following call stack:
System.InvalidOperationException: Unknown agent type
at Microsoft.Exchange.Transport.Categorizer.MExEvents.HandleAgentExchangeExceptions(MExSession MexSession, LocalizedException e)
at Microsoft.Exchange.Transport.Categorizer.MExEvents.EndEvent(MExSession mexSession, IAsyncResult ar)
at Microsoft.Exchange.Transport.Categorizer.CategorizerComponent.HandleMExResult(IAsyncResult result, TransportMailItem transportMailItem, TaskContext taskContext)
at Microsoft.Exchange.Transport.Categorizer.CategorizerComponent.Stage8OnCategorizedMessage(TransportMailItem transportMailItem, TaskContext taskContext)
at Microsoft.Exchange.Transport.Categorizer.TaskContext.Invoke()
at Microsoft.Exchange.Transport.Categorizer.Job.ExecutePendingTasks()
at Microsoft.Exchange.Transport.Categorizer.CatScheduler.JobThreadEntry(Object ignored)
at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
at System.Threading._ThreadPoolWaitCallback.PerformWaitCallbackInternal(_ThreadPoolWaitCallback tpWaitCallBack)
at System.Threading._ThreadPoolWaitCallback.PerformWaitCallback(Object state)

Note This issue may cause a delay in message delivery to users.


This issue occurs because the Microsoft Exchange Transport service incorrectly handles messages that use the character sets that are mentioned in the "Symptoms" section.


To resolve this issue, install the following update rollup:

2661854 Description of Update Rollup 2 for Exchange Server 2010 Service Pack 2


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

More Information

For more information about the Edge Transport server role, visit the following Microsoft website:

General information about the Edge Transport server roleFor more information about charset names, charset values, and code page numbers, visit the following Microsoft website:

General information about charset names, charset values, and code page numbersFor more information about character sets, visit the following Microsoft website:

General information about character setsFor more information about a similar issue, click the following article number to view the article in Microsoft Knowledge Base:

2536702 An email message that contains unsupported encoded characters in the subject line is not delivered in an Exchange Server 2010 environment

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