Files that have the .eml file name extension do not open in Outlook 2007

When you try to open a file that has the .eml file name extension, the file does not open in Microsoft Office Outlook 2007. However, this file opens in Outlook Express, in Windows Mail, and in Internet Explorer.

How to obtain the hotfix

This issue is fixed in the Outlook 2007 post-Service Pack 1 hotfix package that is dated September 24, 2008. For more information, click the following article number to view the article in the Microsoft Knowledge Base:

How to enable the hotfix

Important This section, method, or task contains steps that tell you how to modify the registry. However, serious problems might occur if you modify the registry incorrectly. Therefore, make sure that you follow these steps carefully. For added protection, back up the registry before you modify it. Then, you can restore the registry if a problem occurs. For more information about how to back up and restore the registry, click the following article number to view the article in the Microsoft Knowledge Base:

To activate this hotfix, follow these steps:

1. Close Outlook 2007.
2. Start Registry Editor
   • In Windows Vista, click Start
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     , type regedit in the Start Search box, and then press ENTER.
     
     
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     If you are prompted for an administrator password or confirmation, type your password, or click Continue.
   • In Windows XP, click Start, click Run, type regedit in the Open box, and then click OK.
3. Locate and then click to select the following registry subkey:
   HKEY_CLASSES_ROOT\Microsoft Internet Mail Message\shell\open\command
4. Right-click (Default), and then click Modify.
5. Type "%ProgramFiles%\Microsoft Office\Office12\OUTLOOK.EXE" /eml "%1", and then click OK.
6. On the File menu, click Exit to quit Registry Editor.

After you apply this hotfix package, you can also open the .eml file by following these steps.

Note You do not have to implement the previous registry data if you use the following command-line to open .eml files.

1. Open a Command Prompt window.
   • In Windows Vista, click Start
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     , type command prompt in the Start Search box, and then press ENTER.
     
     
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     If you are prompted for an administrator password or confirmation, type your password, or click Continue.
   • In Windows XP, click Start, click Run, type cmd in the Open box, and then click OK.
2. Type "%ProgramFiles%\Microsoft Office\Office12\OUTLOOK.EXE" /eml "<PathToEmlFile>", and then press ENTER.

Windows Vista

1. Click Start
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   , point to All Programs, click Accessories, and then click Run.
2. In the Open box, type cmd, and then click OK.
   
   
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   If you are prompted for an administrator password or confirmation, type your password, or click Continue.
3. Type "%ProgramFiles%\Microsoft Office\Office12\OUTLOOK.EXE" /eml "<PathToEmlFile>", and then press ENTER.

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