Consider the following scenario:
- You have a MAPI application that uses Microsoft Office Outlook 2007 MAPI or Microsoft Outlook 2010 MAPI in online mode.
- The MAPI application tries to access the Exchange server.
- The MAPI application is multithreaded and reads a stream of data from a Microsoft Exchange Server 2010 server.
Exception of type 'Microsoft.Exchange.RpcClientAccess.BufferTooSmallException' was thrown.Note By default, the RPC Client Access log is located in the following folder:
C:\Program Files\Microsoft\Exchange Server\V14\Logging\RPC Client Access
This issue occurs because the Exchange server returns an ecBufferTooSmall response that the MAPI application cannot handle to a sequence of remote operations. The ecBufferTooSmall response is generated because the Exchange server detects that the sequence of remote operations may cause a potential loop between the server and the MAPI application. Therefore, the read stream operation fails with the MAPI_E_CALL_FAILED error.
To resolve this issue, install the following update rollup:
2685289 Description of Update Rollup 3 for Exchange Server 2010 Service Pack 2After you apply this update rollup, the Exchange Server 2010 server returns the ecBufferTooSmall response only if the following conditions are true:
- The RopReadStream remote operation is the first value in the remote operation package.
- The remote operations package is in the maximum size.
- There are no other remote operations in the remote operation package.
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
For more information about random MAPI_E_CALL_FAILED errors in Exchange Server 2010, go to the following MSDN website:RopReadStream remote operation, go to the following Microsoft website: