Consider the following scenario:

  • You have an environment that has Update Rollup 4 for Microsoft Exchange Server 2010 Service Pack 2 (SP2) or a later update rollup that is earlier than Update Rollup 6 installed.

  • You send an email message that contains an attached Open Office XML document (for example, a .pptx or .docx document) that is missing a file name extension.

In this scenario, the Microsoft Full-Text Engine Filter Daemon (Msftefd.exe) process crashes. Additionally, the following events are logged on the Mailbox server:


This issue occurs because the incorrect file name extension causes a crash when the Exchange search engine indexes the email message.


To resolve this issue, install the following update rollup:

2746164 Description of Update Rollup 6 for Exchange Server 2010 Service Pack 2


To work around this issue, follow these steps:

  1. Click Start, click Run, type regedit in the Open box, and then click OK.

  2. Locate and then select the following registry subkey:


  3. On the Edit menu, point to New, and then click DWORD (32-bit) Value.

  4. Type NeverOverrideAttachmentExtension, and then press Enter.

  5. In the Details pane, right-click NeverOverrideAttachmentExtension, and then click Modify.

  6. In the Value data box, type 1, and then click OK.

  7. Exit Registry Editor.


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 Msftefd.exe process, go to the following website:

General information about the Msftefd.exe processFor more information, click the following article number to view the article in the Microsoft Knowledge Base:

2713339 Multi-Mailbox Search feature returns incorrect results when you perform a complex discovery search in an Exchange Server 2010 environment

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