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Attachment file types restricted by Office Outlook 2007

Updated: April 9, 2009

Applies To: Office Resource Kit

This Office product will reach end of support on October 10, 2017. To stay supported, you will need to upgrade. For more information, see , Resources to help you upgrade your Office 2007 servers and clients.


Topic Last Modified: 2016-11-14

There is restricted access to some attachments in items (such as e-mail messages or appointments) in Microsoft Office Outlook 2007. Files with specific file types can be categorized as Level 1 (the user cannot view the file) or Level 2 (the user can open the file after saving it to disk).


This topic is for Outlook administrators. To learn more about why some Outlook attachments are blocked, see Blocked attachments: The Outlook feature you love to hate. Or learn how to share files with restricted file types by reading Blocked attachments in Outlook.

By default, Outlook classifies a number of file type extensions as Level 1 and blocks files with those extensions from being received by users. As an administrator, you can use Group Policy to manage how a file type is categorized for e-mail attachment blocking. For example, you can change a file type categorization from Level 1 to Level 2 or create a list of Level 2 file types.


There are no Level 2 file types by default.

You can find links to more information about customizing attachment settings in Outlook in the See Also section, which is visible when you are connected to the Internet.

The following table lists Level 1 file types that are blocked under a default installation of Outlook.

File type File description


Access Project Extension (Microsoft)


Access Project (Microsoft)


Executable Application


Active Server Page


BASIC Source Code


Batch Processing


Internet Security Certificate File


Compiled HTML Help


DOS CP/M Command File, Command File for Windows NT




Windows Control Panel Extension (Microsoft)


Certificate File


csh Script


DER Encoded X509 Certificate File


Executable File


FoxPro Compiled Source (Microsoft)


Windows Help File


Hypertext Application


Information or Setup File


IIS Internet Communications Settings (Microsoft)


IIS Internet Service Provider Settings (Microsoft)


Internet Document Set, International Translation


JavaScript Source Code


JScript Encoded Script File


UNIX Shell Script


Windows Shortcut File


Access Module Shortcut (Microsoft)


Access (Microsoft)


Access Diagram Shortcut (Microsoft)


Access Macro Shortcut (Microsoft)


Access Query Shortcut (Microsoft)


Access Report Shortcut (Microsoft)


Access Stored Procedures (Microsoft)


Access Table Shortcut (Microsoft)


Media Attachment Unit


Access View Shortcut (Microsoft)


Access Data Access Page (Microsoft)


Access Add-in (Microsoft), MDA Access 2 Workgroup (Microsoft)


Access Application (Microsoft), MDB Access Database (Microsoft)


Access MDE Database File (Microsoft)


Access Add-in Data (Microsoft)


Access Workgroup Information (Microsoft)


Access Wizard Template (Microsoft)


Microsoft Management Console Snap-in Control File (Microsoft)


Windows PowerShell


Windows PowerShell


Windows PowerShell


Windows PowerShell


Windows PowerShell


Windows PowerShell


Windows Installer File (Microsoft)


Windows Installer Patch


Windows SDK Setup Transform Script


Office Profile Settings File


Visual Test (Microsoft)


Windows Program Information File (Microsoft)


Developer Studio Build Log


Outlook Profile file


Program File


Windows PowerShell


Windows PowerShell


Windows PowerShell


Windows PowerShell


Windows PowerShell


Windows PowerShell


MS Exchange Address Book File, Outlook Personal Folder File (Microsoft)


Registration Information/Key for W95/98, Registry Data File


Windows Explorer Command


Windows Screen Saver


Windows Script Component, Foxpro Screen (Microsoft)


Windows Shortcut into a Document


Shell Scrap Object File


Temporary File/Folder


Internet Location


VBScript File or Any VisualBasic Source


VBScript Encoded Script File


VBScript Script File, Visual Basic for Applications Script


Visual Studio .NET Binary-based Macro Project (Microsoft)


Visio Workspace File (Microsoft)


Windows Script File


Windows Script Component


Windows Script File


Windows Script Host Settings File


Exchange Public Folder Shortcut

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